Problem Relations Network¶

2026-01-102026-01-10

Problems and their related problems. Practice related problems together to reinforce patterns.

LeetCode 3 - Longest Substring Without Repeating Characters · Solution ¶

🟡 Medium — Topics: string, hash_table, sliding_window

📁 View Solution

LeetCode 0159 (metadata not yet added)
🟡 LeetCode 340 - Longest Substring with At Most K Distinct Characters · Solution
🔴 LeetCode 76 - Minimum Window Substring · Solution
🟡 LeetCode 438 - Find All Anagrams in a String · Solution
🟡 LeetCode 209 - Minimum Size Subarray Sum · Solution
🟡 LeetCode 567 - Permutation in String · Solution
🟡 LeetCode 424 - Longest Repeating Character Replacement · Solution

LeetCode 19 - Remove Nth Node From End of List · Solution ¶

🟡 Medium — Topics: linked_list, two_pointers

📁 View Solution

🟢 LeetCode 21 - Merge Two Sorted Lists · Solution
🔴 LeetCode 23 - Merge k Sorted Lists · Solution
LeetCode 0061 (metadata not yet added)
LeetCode 0082 (metadata not yet added)
LeetCode 0083 (metadata not yet added)
🟢 LeetCode 141 - Linked List Cycle · Solution
🟢 LeetCode 206 - Reverse Linked List · Solution

LeetCode 994 - Rotting Oranges · Solution ¶

🟡 Medium — Topics: array, breadth_first_search, matrix

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🟡 LeetCode 286 - Walls and Gates · Solution
🟡 LeetCode 542 - 01 Matrix · Solution
🔴 LeetCode 127 - Word Ladder · Solution
LeetCode 0752 (metadata not yet added)
LeetCode 1091 (metadata not yet added)
🟡 LeetCode 200 - Number of Islands · Solution

LeetCode 2 - Add Two Numbers · Solution ¶

🟡 Medium — Topics: linked_list, math, recursion

📁 View Solution

🟡 LeetCode 43 - Multiply Strings · Solution
LeetCode 0067 (metadata not yet added)
🟡 LeetCode 371 - Sum of Two Integers · Solution
LeetCode 0415 (metadata not yet added)
LeetCode 0445 (metadata not yet added)

LeetCode 17 - Letter Combinations of a Phone Number · Solution ¶

🟡 Medium — Topics: hash_table, string, backtracking

📁 View Solution

🟡 LeetCode 22 - Generate Parentheses · Solution
🟡 LeetCode 39 - Combination Sum · Solution
🟡 LeetCode 46 - Permutations · Solution
🟡 LeetCode 77 - Combinations · Solution
🟡 LeetCode 78 - Subsets · Solution

LeetCode 76 - Minimum Window Substring · Solution ¶

🔴 Hard — Topics: string, hash_table, sliding_window

📁 View Solution

🟡 LeetCode 3 - Longest Substring Without Repeating Characters · Solution
LeetCode 0030 (metadata not yet added)
🟡 LeetCode 209 - Minimum Size Subarray Sum · Solution
🟡 LeetCode 438 - Find All Anagrams in a String · Solution
🟡 LeetCode 567 - Permutation in String · Solution

LeetCode 200 - Number of Islands · Solution ¶

🟡 Medium — Topics: array, depth_first_search, breadth_first_search

📁 View Solution

🟡 LeetCode 695 - Max Area of Island · Solution
LeetCode 0463 (metadata not yet added)
LeetCode 0827 (metadata not yet added)
🟡 LeetCode 130 - Surrounded Regions · Solution
🟡 LeetCode 417 - Pacific Atlantic Water Flow · Solution

LeetCode 209 - Minimum Size Subarray Sum · Solution ¶

🟡 Medium — Topics: array, binary_search, sliding_window

📁 View Solution

🟡 LeetCode 3 - Longest Substring Without Repeating Characters · Solution
🔴 LeetCode 76 - Minimum Window Substring · Solution
LeetCode 0325 (metadata not yet added)
LeetCode 0718 (metadata not yet added)
🔴 LeetCode 862 - Shortest Subarray with Sum at Least K · Solution

LeetCode 340 - Longest Substring with At Most K Distinct Characters · Solution ¶

🟡 Medium — Topics: string, hash_table, sliding_window

📁 View Solution

🟡 LeetCode 3 - Longest Substring Without Repeating Characters · Solution
LeetCode 0159 (metadata not yet added)
🔴 LeetCode 76 - Minimum Window Substring · Solution
🟡 LeetCode 424 - Longest Repeating Character Replacement · Solution
LeetCode 0904 (metadata not yet added)

LeetCode 2029 - Stone Game IX · Solution ¶

🟡 Medium — Topics: array, math, counting

📁 View Solution

🟡 LeetCode 877 - Stone Game
LeetCode 1140 (metadata not yet added)
🔴 LeetCode 1406 - Stone Game III
LeetCode 1563 (metadata not yet added)
LeetCode 1686 (metadata not yet added)

LeetCode 1 - Two Sum · Solution ¶

🟢 Easy — Topics: array, hash_table

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🟡 LeetCode 15 - 3Sum · Solution
LeetCode 0167 (metadata not yet added)
LeetCode 0170 (metadata not yet added)
LeetCode 0653 (metadata not yet added)

LeetCode 5 - Longest Palindromic Substring · Solution ¶

🟡 Medium — Topics: string, dynamic_programming

📁 View Solution

🟡 LeetCode 516 - Longest Palindromic Subsequence · Solution
🟡 LeetCode 647 - Palindromic Substrings · Solution
🔴 LeetCode 214 - Shortest Palindrome
🟡 LeetCode 131 - Palindrome Partitioning · Solution

LeetCode 15 - 3Sum · Solution ¶

🟡 Medium — Topics: array, two_pointers, sorting

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🟢 LeetCode 1 - Two Sum · Solution
🟡 LeetCode 16 - 3Sum Closest · Solution
LeetCode 0018 (metadata not yet added)
LeetCode 0167 (metadata not yet added)

LeetCode 20 - Valid Parentheses · Solution ¶

🟢 Easy — Topics: string, stack

📁 View Solution

🟡 LeetCode 22 - Generate Parentheses · Solution
LeetCode 0032 (metadata not yet added)
LeetCode 0921 (metadata not yet added)
LeetCode 1541 (metadata not yet added)

LeetCode 23 - Merge k Sorted Lists · Solution ¶

🔴 Hard — Topics: linked_list, divide_and_conquer, heap

📁 View Solution

🟢 LeetCode 21 - Merge Two Sorted Lists · Solution
🔴 LeetCode 4 - Median of Two Sorted Arrays · Solution
LeetCode 0378 (metadata not yet added)
LeetCode 0264 (metadata not yet added)

LeetCode 33 - Search in Rotated Sorted Array · Solution ¶

🟡 Medium — Topics: array, binary_search

📁 View Solution

🟡 LeetCode 81 - Search in Rotated Sorted Array II · Solution
🟡 LeetCode 153 - Find Minimum in Rotated Sorted Array · Solution
LeetCode 0154 (metadata not yet added)
🟡 LeetCode 33 - Search in Rotated Sorted Array · Solution

LeetCode 39 - Combination Sum · Solution ¶

🟡 Medium — Topics: array, backtracking

📁 View Solution

🟡 LeetCode 40 - Combination Sum II · Solution
🟡 LeetCode 77 - Combinations · Solution
🟡 LeetCode 216 - Combination Sum III · Solution
🟡 LeetCode 78 - Subsets · Solution

LeetCode 40 - Combination Sum II · Solution ¶

🟡 Medium — Topics: array, backtracking

📁 View Solution

🟡 LeetCode 39 - Combination Sum · Solution
🟡 LeetCode 90 - Subsets II · Solution
🟡 LeetCode 47 - Permutations II · Solution
🟡 LeetCode 216 - Combination Sum III · Solution

LeetCode 56 - Merge Intervals · Solution ¶

🟡 Medium — Topics: array, sorting

📁 View Solution

🟡 LeetCode 57 - Insert Interval · Solution
🟡 LeetCode 435 - Non-overlapping Intervals · Solution
🟢 LeetCode 252 - Meeting Rooms · Solution
🟡 LeetCode 253 - Meeting Rooms II · Solution

LeetCode 72 - Edit Distance · Solution ¶

🟡 Medium — Topics: String, Dynamic Programming

📁 View Solution

🟡 LeetCode 1143 - Longest Common Subsequence · Solution
LeetCode 0583 (metadata not yet added)
LeetCode 0712 (metadata not yet added)
LeetCode 0161 (metadata not yet added)

LeetCode 102 - Binary Tree Level Order Traversal · Solution ¶

🟡 Medium — Topics: tree, breadth_first_search, binary_tree

📁 View Solution

LeetCode 0103 (metadata not yet added)
LeetCode 0107 (metadata not yet added)
🟡 LeetCode 199 - Binary Tree Right Side View · Solution
LeetCode 0637 (metadata not yet added)

LeetCode 115 - Distinct Subsequences · Solution ¶

🔴 Hard — Topics: string, dynamic_programming

📁 View Solution

🟡 LeetCode 72 - Edit Distance · Solution
LeetCode 0583 (metadata not yet added)
🟡 LeetCode 1143 - Longest Common Subsequence · Solution
🟡 LeetCode 97 - Interleaving String · Solution

LeetCode 124 - Binary Tree Maximum Path Sum · Solution ¶

🔴 Hard — Topics: dynamic_programming, tree, depth_first_search

📁 View Solution

🟢 LeetCode 543 - Diameter of Binary Tree · Solution
LeetCode 0112 (metadata not yet added)
LeetCode 0687 (metadata not yet added)
LeetCode 0129 (metadata not yet added)

LeetCode 208 - Implement Trie (Prefix Tree) · Solution(Prefix Tree)¶

🟡 Medium — Topics: hash_table, string, design

📁 View Solution

🟡 LeetCode 211 - Design Add and Search Words Data Structure · Solution
🔴 LeetCode 212 - Word Search II · Solution
🟡 LeetCode 648 - Replace Words · Solution
🟡 LeetCode 1268 - Search Suggestions System · Solution

LeetCode 211 - Design Add and Search Words Data Structure · Solution ¶

🟡 Medium — Topics: string, depth_first_search, design

📁 View Solution

🟡 LeetCode 208 - Implement Trie (Prefix Tree) · Solution(Prefix Tree)
🔴 LeetCode 212 - Word Search II · Solution
🟡 LeetCode 648 - Replace Words · Solution
🟡 LeetCode 1268 - Search Suggestions System · Solution

LeetCode 253 - Meeting Rooms II · Solution ¶

🟡 Medium — Topics: array, two_pointers, greedy

📁 View Solution

🟢 LeetCode 252 - Meeting Rooms · Solution
🟡 LeetCode 56 - Merge Intervals · Solution
🟡 LeetCode 435 - Non-overlapping Intervals · Solution
🟡 LeetCode 1094 - Car Pooling · Solution

LeetCode 300 - Longest Increasing Subsequence · Solution ¶

🟡 Medium — Topics: array, binary_search, dynamic_programming

📁 View Solution

LeetCode 0334 (metadata not yet added)
LeetCode 0354 (metadata not yet added)
LeetCode 0646 (metadata not yet added)
LeetCode 0673 (metadata not yet added)

LeetCode 309 - Best Time to Buy and Sell Stock with Cooldown · Solution ¶

🟡 Medium — Topics: array, dynamic_programming

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🟢 LeetCode 121 - Best Time to Buy and Sell Stock · Solution
LeetCode 0122 (metadata not yet added)
LeetCode 0188 (metadata not yet added)
LeetCode 0714 (metadata not yet added)

LeetCode 438 - Find All Anagrams in a String · Solution ¶

🟡 Medium — Topics: string, hash_table, sliding_window

📁 View Solution

🟡 LeetCode 3 - Longest Substring Without Repeating Characters · Solution
🔴 LeetCode 76 - Minimum Window Substring · Solution
🟢 LeetCode 242 - Valid Anagram · Solution
🟡 LeetCode 567 - Permutation in String · Solution

LeetCode 516 - Longest Palindromic Subsequence · Solution ¶

🟡 Medium — Topics: String, Dynamic Programming

📁 View Solution

🟡 LeetCode 1143 - Longest Common Subsequence · Solution
🟡 LeetCode 5 - Longest Palindromic Substring · Solution
🟡 LeetCode 647 - Palindromic Substrings · Solution
LeetCode 1312 (metadata not yet added)

LeetCode 543 - Diameter of Binary Tree · Solution ¶

🟢 Easy — Topics: tree, depth_first_search, binary_tree

📁 View Solution

🟢 LeetCode 104 - Maximum Depth of Binary Tree · Solution
🔴 LeetCode 124 - Binary Tree Maximum Path Sum · Solution
LeetCode 0687 (metadata not yet added)
LeetCode 1522 (metadata not yet added)

LeetCode 560 - Subarray Sum Equals K · Solution ¶

🟡 Medium — Topics: array, hash_table, prefix_sum

📁 View Solution

🟢 LeetCode 303 - Range Sum Query - Immutable · Solution
🟡 LeetCode 525 - Contiguous Array · Solution
🟡 LeetCode 523 - Continuous Subarray Sum · Solution
LeetCode 0974 (metadata not yet added)

LeetCode 567 - Permutation in String · Solution ¶

🟡 Medium — Topics: string, hash_table, two_pointers

📁 View Solution

🟡 LeetCode 3 - Longest Substring Without Repeating Characters · Solution
🔴 LeetCode 76 - Minimum Window Substring · Solution
🟢 LeetCode 242 - Valid Anagram · Solution
🟡 LeetCode 438 - Find All Anagrams in a String · Solution

LeetCode 648 - Replace Words · Solution ¶

🟡 Medium — Topics: array, hash_table, string

📁 View Solution

🟡 LeetCode 208 - Implement Trie (Prefix Tree) · Solution(Prefix Tree)
🟡 LeetCode 211 - Design Add and Search Words Data Structure · Solution
🔴 LeetCode 212 - Word Search II · Solution
🟡 LeetCode 1268 - Search Suggestions System · Solution

LeetCode 743 - Network Delay Time · Solution ¶

🟡 Medium — Topics: depth_first_search, breadth_first_search, graph

📁 View Solution

LeetCode 778 - Swim in Rising Water · Solution ¶

🔴 Hard — Topics: array, binary_search, dfs

📁 View Solution

🟡 LeetCode 743 - Network Delay Time · Solution
🟡 LeetCode 787 - Cheapest Flights Within K Stops · Solution
LeetCode 1102 (metadata not yet added)
🟡 LeetCode 1631 - Path With Minimum Effort · Solution

LeetCode 787 - Cheapest Flights Within K Stops · Solution ¶

🟡 Medium — Topics: dynamic_programming, depth_first_search, breadth_first_search

📁 View Solution

🟡 LeetCode 743 - Network Delay Time · Solution
🟡 LeetCode 1631 - Path With Minimum Effort · Solution
🔴 LeetCode 1368 - Minimum Cost to Make at Least One Valid Path in a Grid · Solution
🔴 LeetCode 2290 - Minimum Obstacle Removal to Reach Corner · Solution

LeetCode 862 - Shortest Subarray with Sum at Least K · Solution ¶

🔴 Hard — Topics: array, binary_search, queue

📁 View Solution

🔴 LeetCode 239 - Sliding Window Maximum · Solution
🟡 LeetCode 1438 - Longest Continuous Subarray With Absolute Diff Less Than or Equal to Limit · Solution
🔴 LeetCode 1499 - Max Value of Equation · Solution
🟡 LeetCode 209 - Minimum Size Subarray Sum · Solution

LeetCode 875 - Koko Eating Bananas · Solution ¶

🟡 Medium — Topics: array, binary_search

📁 View Solution

🟡 LeetCode 1011 - Capacity To Ship Packages Within D Days · Solution
LeetCode 0410 (metadata not yet added)
LeetCode 1482 (metadata not yet added)
LeetCode 2064 (metadata not yet added)

LeetCode 1011 - Capacity To Ship Packages Within D Days · Solution ¶

🟡 Medium — Topics: array, binary_search

📁 View Solution

🟡 LeetCode 875 - Koko Eating Bananas · Solution
LeetCode 0410 (metadata not yet added)
LeetCode 1482 (metadata not yet added)
LeetCode 2064 (metadata not yet added)

LeetCode 1143 - Longest Common Subsequence · Solution ¶

🟡 Medium — Topics: String, Dynamic Programming

📁 View Solution

🟡 LeetCode 72 - Edit Distance · Solution
🟡 LeetCode 516 - Longest Palindromic Subsequence · Solution
LeetCode 0583 (metadata not yet added)
LeetCode 1092 (metadata not yet added)

LeetCode 1268 - Search Suggestions System · Solution ¶

🟡 Medium — Topics: array, string, binary_search

📁 View Solution

🟡 LeetCode 208 - Implement Trie (Prefix Tree) · Solution(Prefix Tree)
🟡 LeetCode 211 - Design Add and Search Words Data Structure · Solution
🔴 LeetCode 212 - Word Search II · Solution
🟡 LeetCode 648 - Replace Words · Solution

LeetCode 1368 - Minimum Cost to Make at Least One Valid Path in a Grid · Solution ¶

🔴 Hard — Topics: array, breadth_first_search, graph

📁 View Solution

🟡 LeetCode 743 - Network Delay Time · Solution
🟡 LeetCode 1631 - Path With Minimum Effort · Solution
🟡 LeetCode 787 - Cheapest Flights Within K Stops · Solution
🔴 LeetCode 2290 - Minimum Obstacle Removal to Reach Corner · Solution

LeetCode 1448 - Count Good Nodes in Binary Tree · Solution ¶

🟡 Medium — Topics: tree, dfs, bfs

📁 View Solution

🟢 LeetCode 104 - Maximum Depth of Binary Tree · Solution
LeetCode 0112 (metadata not yet added)
🔴 LeetCode 124 - Binary Tree Maximum Path Sum · Solution
🟢 LeetCode 543 - Diameter of Binary Tree · Solution

LeetCode 1584 - Min Cost to Connect All Points · Solution ¶

🟡 Medium — Topics: array, union_find, graph

📁 View Solution

🔴 LeetCode 778 - Swim in Rising Water · Solution
LeetCode 1135 (metadata not yet added)
LeetCode 1168 (metadata not yet added)
LeetCode 1489 (metadata not yet added)

LeetCode 1631 - Path With Minimum Effort · Solution ¶

🟡 Medium — Topics: array, binary_search, breadth_first_search

📁 View Solution

🟡 LeetCode 743 - Network Delay Time · Solution
🟡 LeetCode 787 - Cheapest Flights Within K Stops · Solution
🔴 LeetCode 1368 - Minimum Cost to Make at Least One Valid Path in a Grid · Solution
🔴 LeetCode 2290 - Minimum Obstacle Removal to Reach Corner · Solution

LeetCode 1851 - Minimum Interval to Include Each Query · Solution ¶

🔴 Hard — Topics: array, binary_search, line_sweep

📁 View Solution

🟡 LeetCode 56 - Merge Intervals · Solution
🟡 LeetCode 57 - Insert Interval · Solution
🟡 LeetCode 253 - Meeting Rooms II · Solution
🟡 LeetCode 435 - Non-overlapping Intervals · Solution

LeetCode 1871 - Jump Game VII · Solution ¶

🟡 Medium — Topics: string, dynamic_programming, sliding_window

📁 View Solution

🟡 LeetCode 55 - Jump Game · Solution
🟡 LeetCode 45 - Jump Game II · Solution
LeetCode 1306 (metadata not yet added)
LeetCode 1345 (metadata not yet added)

LeetCode 2290 - Minimum Obstacle Removal to Reach Corner · Solution ¶

🔴 Hard — Topics: array, breadth_first_search, graph

📁 View Solution

🟡 LeetCode 743 - Network Delay Time · Solution
🟡 LeetCode 1631 - Path With Minimum Effort · Solution
🟡 LeetCode 787 - Cheapest Flights Within K Stops · Solution
🔴 LeetCode 1368 - Minimum Cost to Make at Least One Valid Path in a Grid · Solution

LeetCode 2741 - Special Permutations · Solution ¶

🟡 Medium — Topics: array, dynamic-programming, bit-manipulation

📁 View Solution

🟡 LeetCode 46 - Permutations · Solution
🟡 LeetCode 78 - Subsets · Solution
LeetCode 0698 (metadata not yet added)
LeetCode 0526 (metadata not yet added)

LeetCode 4 - Median of Two Sorted Arrays · Solution ¶

🔴 Hard — Topics: array, binary_search, divide_and_conquer

📁 View Solution

🔴 LeetCode 23 - Merge k Sorted Lists · Solution
🟢 LeetCode 21 - Merge Two Sorted Lists · Solution
🟡 LeetCode 215 - Kth Largest Element in an Array · Solution

LeetCode 7 - Reverse Integer · Solution ¶

🟡 Medium — Topics: math

📁 View Solution

🟡 LeetCode 8 - String to Integer (atoi) · Solution(atoi)
LeetCode 0009 (metadata not yet added)
🟢 LeetCode 190 - Reverse Bits · Solution

LeetCode 11 - Container With Most Water · Solution ¶

🟡 Medium — Topics: array, two_pointers, greedy

📁 View Solution

🔴 LeetCode 42 - Trapping Rain Water · Solution
🟢 LeetCode 125 - Valid Palindrome · Solution
LeetCode 0167 (metadata not yet added)

LeetCode 21 - Merge Two Sorted Lists · Solution ¶

🟢 Easy — Topics: linked_list, recursion

📁 View Solution

🔴 LeetCode 23 - Merge k Sorted Lists · Solution
🟢 LeetCode 88 - Merge Sorted Array · Solution
🟢 LeetCode 977 - Squares of a Sorted Array · Solution

LeetCode 22 - Generate Parentheses · Solution ¶

🟡 Medium — Topics: string, dynamic_programming, backtracking

📁 View Solution

🟡 LeetCode 17 - Letter Combinations of a Phone Number · Solution
🟢 LeetCode 20 - Valid Parentheses · Solution
LeetCode 0032 (metadata not yet added)

LeetCode 25 - Reverse Nodes in k-Group · Solution ¶

🔴 Hard — Topics: linked_list, recursion

📁 View Solution

LeetCode 0024 (metadata not yet added)
🟢 LeetCode 206 - Reverse Linked List · Solution
🟡 LeetCode 92 - Reverse Linked List II · Solution

LeetCode 26 - Remove Duplicates from Sorted Array · Solution ¶

🟢 Easy — Topics: array, two_pointers

📁 View Solution

🟢 LeetCode 27 - Remove Element · Solution
🟡 LeetCode 80 - Remove Duplicates from Sorted Array II · Solution
🟢 LeetCode 283 - Move Zeroes · Solution

LeetCode 31 - Next Permutation · Solution ¶

🟡 Medium — Topics: array, two_pointers

📁 View Solution

🟡 LeetCode 46 - Permutations · Solution
🟡 LeetCode 47 - Permutations II · Solution
LeetCode 0060 (metadata not yet added)

LeetCode 34 - Find First and Last Position of Element in Sorted Array · Solution ¶

🟡 Medium — Topics: array, binary_search

📁 View Solution

🟢 LeetCode 35 - Search Insert Position · Solution
LeetCode 0278 (metadata not yet added)
🟢 LeetCode 704 - Binary Search · Solution

LeetCode 35 - Search Insert Position · Solution ¶

🟢 Easy — Topics: array, binary_search

📁 View Solution

🟡 LeetCode 34 - Find First and Last Position of Element in Sorted Array · Solution
🟢 LeetCode 704 - Binary Search · Solution
LeetCode 0278 (metadata not yet added)

LeetCode 42 - Trapping Rain Water · Solution ¶

🔴 Hard — Topics: array, two_pointers, dynamic_programming

📁 View Solution

🟡 LeetCode 11 - Container With Most Water · Solution
🔴 LeetCode 84 - Largest Rectangle in Histogram · Solution
LeetCode 0407 (metadata not yet added)

LeetCode 43 - Multiply Strings · Solution ¶

🟡 Medium — Topics: math, string, simulation

📁 View Solution

🟡 LeetCode 2 - Add Two Numbers · Solution
🟢 LeetCode 66 - Plus One · Solution
LeetCode 0067 (metadata not yet added)

LeetCode 46 - Permutations · Solution ¶

🟡 Medium — Topics: array, backtracking

📁 View Solution

🟡 LeetCode 47 - Permutations II · Solution
🟡 LeetCode 78 - Subsets · Solution
🟡 LeetCode 77 - Combinations · Solution

LeetCode 47 - Permutations II · Solution ¶

🟡 Medium — Topics: array, backtracking

📁 View Solution

🟡 LeetCode 46 - Permutations · Solution
🟡 LeetCode 40 - Combination Sum II · Solution
🟡 LeetCode 90 - Subsets II · Solution

LeetCode 48 - Rotate Image · Solution ¶

🟡 Medium — Topics: array, math, matrix

📁 View Solution

🟡 LeetCode 54 - Spiral Matrix · Solution
LeetCode 0059 (metadata not yet added)
🟡 LeetCode 73 - Set Matrix Zeroes · Solution

LeetCode 53 - Maximum Subarray · Solution ¶

🟡 Medium — Topics: array, divide_and_conquer, dynamic_programming

📁 View Solution

🟢 LeetCode 121 - Best Time to Buy and Sell Stock · Solution
🟡 LeetCode 152 - Maximum Product Subarray · Solution
LeetCode 0918 (metadata not yet added)

LeetCode 54 - Spiral Matrix · Solution ¶

🟡 Medium — Topics: array, matrix, simulation

📁 View Solution

🟡 LeetCode 48 - Rotate Image · Solution
LeetCode 0059 (metadata not yet added)
LeetCode 0885 (metadata not yet added)

LeetCode 57 - Insert Interval · Solution ¶

🟡 Medium — Topics: array

📁 View Solution

🟡 LeetCode 56 - Merge Intervals · Solution
LeetCode 0715 (metadata not yet added)
LeetCode 0352 (metadata not yet added)

LeetCode 62 - Unique Paths · Solution ¶

🟡 Medium — Topics: math, dynamic_programming, combinatorics

📁 View Solution

LeetCode 0063 (metadata not yet added)
LeetCode 0064 (metadata not yet added)
LeetCode 0980 (metadata not yet added)

LeetCode 66 - Plus One · Solution ¶

🟢 Easy — Topics: array, math

📁 View Solution

LeetCode 0067 (metadata not yet added)
LeetCode 0369 (metadata not yet added)
LeetCode 0989 (metadata not yet added)

LeetCode 77 - Combinations · Solution ¶

🟡 Medium — Topics: backtracking

📁 View Solution

🟡 LeetCode 78 - Subsets · Solution
🟡 LeetCode 39 - Combination Sum · Solution
🟡 LeetCode 216 - Combination Sum III · Solution

LeetCode 78 - Subsets · Solution ¶

🟡 Medium — Topics: array, backtracking, bit_manipulation

📁 View Solution

LeetCode 79 - Word Search · Solution ¶

🟡 Medium — Topics: array, backtracking, matrix

📁 View Solution

🔴 LeetCode 212 - Word Search II · Solution
🟡 LeetCode 130 - Surrounded Regions · Solution
🟡 LeetCode 200 - Number of Islands · Solution

LeetCode 81 - Search in Rotated Sorted Array II · Solution ¶

🟡 Medium — Topics: array, binary_search

📁 View Solution

🟡 LeetCode 33 - Search in Rotated Sorted Array · Solution
🟡 LeetCode 153 - Find Minimum in Rotated Sorted Array · Solution
LeetCode 0154 (metadata not yet added)

LeetCode 90 - Subsets II · Solution ¶

🟡 Medium — Topics: array, backtracking, bit_manipulation

📁 View Solution

🟡 LeetCode 78 - Subsets · Solution
🟡 LeetCode 40 - Combination Sum II · Solution
🟡 LeetCode 47 - Permutations II · Solution

LeetCode 91 - Decode Ways · Solution ¶

🟡 Medium — Topics: string, dynamic_programming

📁 View Solution

🟡 LeetCode 62 - Unique Paths · Solution
🟢 LeetCode 70 - Climbing Stairs · Solution
LeetCode 0639 (metadata not yet added)

LeetCode 94 - Binary Tree Inorder Traversal · Solution ¶

🟢 Easy — Topics: stack, tree, depth_first_search

📁 View Solution

LeetCode 0144 (metadata not yet added)
LeetCode 0145 (metadata not yet added)
🟡 LeetCode 102 - Binary Tree Level Order Traversal · Solution

LeetCode 97 - Interleaving String · Solution ¶

🟡 Medium — Topics: string, dynamic_programming

📁 View Solution

🔴 LeetCode 115 - Distinct Subsequences · Solution
🟡 LeetCode 1143 - Longest Common Subsequence · Solution
🟡 LeetCode 72 - Edit Distance · Solution

LeetCode 98 - Validate Binary Search Tree · Solution ¶

🟡 Medium — Topics: tree, binary_search_tree, dfs

📁 View Solution

🟢 LeetCode 94 - Binary Tree Inorder Traversal · Solution
LeetCode 0501 (metadata not yet added)
LeetCode 0530 (metadata not yet added)

LeetCode 100 - Same Tree · Solution ¶

🟢 Easy — Topics: tree, depth_first_search, breadth_first_search

📁 View Solution

LeetCode 0101 (metadata not yet added)
🟢 LeetCode 104 - Maximum Depth of Binary Tree · Solution
🟢 LeetCode 572 - Subtree of Another Tree · Solution

LeetCode 104 - Maximum Depth of Binary Tree · Solution ¶

🟢 Easy — Topics: tree, depth_first_search, breadth_first_search

📁 View Solution

LeetCode 0111 (metadata not yet added)
🟢 LeetCode 110 - Balanced Binary Tree · Solution
🟢 LeetCode 543 - Diameter of Binary Tree · Solution

LeetCode 110 - Balanced Binary Tree · Solution ¶

🟢 Easy — Topics: tree, depth_first_search, binary_tree

📁 View Solution

🟢 LeetCode 104 - Maximum Depth of Binary Tree · Solution
🟢 LeetCode 543 - Diameter of Binary Tree · Solution
LeetCode 0111 (metadata not yet added)

LeetCode 125 - Valid Palindrome · Solution ¶

🟢 Easy — Topics: two_pointers, string

📁 View Solution

🟢 LeetCode 680 - Valid Palindrome II · Solution
🟡 LeetCode 5 - Longest Palindromic Substring · Solution
🟢 LeetCode 125 - Valid Palindrome · Solution

LeetCode 127 - Word Ladder · Solution ¶

🔴 Hard — Topics: hash_table, string, breadth_first_search

📁 View Solution

🔴 LeetCode 126 - Word Ladder II · Solution
LeetCode 0433 (metadata not yet added)
LeetCode 0752 (metadata not yet added)

LeetCode 130 - Surrounded Regions · Solution ¶

🟡 Medium — Topics: array, depth_first_search, breadth_first_search

📁 View Solution

🟡 LeetCode 200 - Number of Islands · Solution
🟡 LeetCode 286 - Walls and Gates · Solution
🟡 LeetCode 417 - Pacific Atlantic Water Flow · Solution

LeetCode 136 - Single Number · Solution ¶

🟢 Easy — Topics: array, bit_manipulation

📁 View Solution

LeetCode 0137 (metadata not yet added)
LeetCode 0260 (metadata not yet added)
🟢 LeetCode 268 - Missing Number · Solution

LeetCode 143 - Reorder List · Solution ¶

🟡 Medium — Topics: linked_list, two_pointers, stack

📁 View Solution

🟢 LeetCode 206 - Reverse Linked List · Solution
🟢 LeetCode 876 - Middle of the Linked List · Solution
LeetCode 0234 (metadata not yet added)

LeetCode 146 - LRU Cache · Solution ¶

🟡 Medium — Topics: hash_table, linked_list, design

📁 View Solution

LeetCode 0460 (metadata not yet added)
LeetCode 0432 (metadata not yet added)
LeetCode 0588 (metadata not yet added)

LeetCode 150 - Evaluate Reverse Polish Notation · Solution ¶

🟡 Medium — Topics: array, math, stack

📁 View Solution

LeetCode 0224 (metadata not yet added)
LeetCode 0227 (metadata not yet added)
LeetCode 0772 (metadata not yet added)

LeetCode 152 - Maximum Product Subarray · Solution ¶

🟡 Medium — Topics: array, dynamic_programming

📁 View Solution

🟡 LeetCode 53 - Maximum Subarray · Solution
LeetCode 0628 (metadata not yet added)
🟡 LeetCode 238 - Product of Array Except Self · Solution

LeetCode 153 - Find Minimum in Rotated Sorted Array · Solution ¶

🟡 Medium — Topics: array, binary_search

📁 View Solution

🟡 LeetCode 33 - Search in Rotated Sorted Array · Solution
LeetCode 0154 (metadata not yet added)
🟡 LeetCode 81 - Search in Rotated Sorted Array II · Solution

LeetCode 162 - Find Peak Element · Solution ¶

🟡 Medium — Topics: array, binary_search

📁 View Solution

LeetCode 0852 (metadata not yet added)
LeetCode 1095 (metadata not yet added)
🟡 LeetCode 153 - Find Minimum in Rotated Sorted Array · Solution

LeetCode 190 - Reverse Bits · Solution ¶

🟢 Easy — Topics: divide_and_conquer, bit_manipulation

📁 View Solution

🟡 LeetCode 7 - Reverse Integer · Solution
🟢 LeetCode 191 - Number of 1 Bits · Solution
🟢 LeetCode 338 - Counting Bits · Solution

LeetCode 191 - Number of 1 Bits · Solution ¶

🟢 Easy — Topics: divide_and_conquer, bit_manipulation

📁 View Solution

🟢 LeetCode 190 - Reverse Bits · Solution
LeetCode 0231 (metadata not yet added)
🟢 LeetCode 338 - Counting Bits · Solution

LeetCode 199 - Binary Tree Right Side View · Solution ¶

🟡 Medium — Topics: tree, depth_first_search, breadth_first_search

📁 View Solution

🟡 LeetCode 102 - Binary Tree Level Order Traversal · Solution
LeetCode 0116 (metadata not yet added)
LeetCode 0545 (metadata not yet added)

LeetCode 206 - Reverse Linked List · Solution ¶

🟢 Easy — Topics: linked_list, recursion

📁 View Solution

🟡 LeetCode 92 - Reverse Linked List II · Solution
🔴 LeetCode 25 - Reverse Nodes in k-Group · Solution
LeetCode 0234 (metadata not yet added)

LeetCode 207 - Course Schedule · Solution ¶

🟡 Medium — Topics: depth_first_search, breadth_first_search, graph

📁 View Solution

🟡 LeetCode 210 - Course Schedule II · Solution
🟡 LeetCode 802 - Find Eventual Safe States · Solution
🔴 LeetCode 1203 - Sort Items by Groups Respecting Dependencies · Solution

LeetCode 210 - Course Schedule II · Solution ¶

🟡 Medium — Topics: depth_first_search, breadth_first_search, graph

📁 View Solution

🟡 LeetCode 207 - Course Schedule · Solution
🟡 LeetCode 802 - Find Eventual Safe States · Solution
🔴 LeetCode 1203 - Sort Items by Groups Respecting Dependencies · Solution

LeetCode 212 - Word Search II · Solution ¶

🔴 Hard — Topics: array, string, backtracking

📁 View Solution

🟡 LeetCode 208 - Implement Trie (Prefix Tree) · Solution(Prefix Tree)
🟡 LeetCode 211 - Design Add and Search Words Data Structure · Solution
🟡 LeetCode 79 - Word Search · Solution

LeetCode 216 - Combination Sum III · Solution ¶

🟡 Medium — Topics: array, backtracking

📁 View Solution

🟡 LeetCode 39 - Combination Sum · Solution
🟡 LeetCode 40 - Combination Sum II · Solution
🟡 LeetCode 77 - Combinations · Solution

LeetCode 217 - Contains Duplicate · Solution ¶

🟢 Easy — Topics: array, hash_table, sorting

📁 View Solution

LeetCode 0219 (metadata not yet added)
🔴 LeetCode 220 - Contains Duplicate III · Solution
LeetCode 0287 (metadata not yet added)

LeetCode 226 - Invert Binary Tree · Solution ¶

🟢 Easy — Topics: tree, depth_first_search, breadth_first_search

📁 View Solution

LeetCode 0101 (metadata not yet added)
🟢 LeetCode 104 - Maximum Depth of Binary Tree · Solution
🟢 LeetCode 110 - Balanced Binary Tree · Solution

LeetCode 230 - Kth Smallest Element in a BST · Solution ¶

🟡 Medium — Topics: tree, depth_first_search, binary_search_tree

📁 View Solution

🟢 LeetCode 94 - Binary Tree Inorder Traversal · Solution
LeetCode 0144 (metadata not yet added)
LeetCode 0270 (metadata not yet added)

LeetCode 235 - Lowest Common Ancestor of a Binary Search Tree · Solution ¶

🟡 Medium — Topics: tree, depth_first_search, binary_search_tree

📁 View Solution

LeetCode 0236 (metadata not yet added)
LeetCode 0700 (metadata not yet added)
LeetCode 0701 (metadata not yet added)

LeetCode 239 - Sliding Window Maximum · Solution ¶

🔴 Hard — Topics: array, queue, sliding_window

📁 View Solution

LeetCode 242 - Valid Anagram · Solution ¶

🟢 Easy — Topics: hash_table, string, sorting

📁 View Solution

🟡 LeetCode 49 - Group Anagrams · Solution
LeetCode 0266 (metadata not yet added)
🟡 LeetCode 438 - Find All Anagrams in a String · Solution

LeetCode 252 - Meeting Rooms · Solution ¶

🟢 Easy — Topics: array, sorting

📁 View Solution

🟡 LeetCode 253 - Meeting Rooms II · Solution
🟡 LeetCode 56 - Merge Intervals · Solution
🟡 LeetCode 435 - Non-overlapping Intervals · Solution

LeetCode 261 - Graph Valid Tree · Solution ¶

🟡 Medium — Topics: graph, dfs, bfs

📁 View Solution

🟡 LeetCode 200 - Number of Islands · Solution
🟡 LeetCode 684 - Redundant Connection · Solution
LeetCode 0323 (metadata not yet added)

LeetCode 268 - Missing Number · Solution ¶

🟢 Easy — Topics: array, hash_table, math

📁 View Solution

LeetCode 0041 (metadata not yet added)
🟢 LeetCode 136 - Single Number · Solution
LeetCode 0287 (metadata not yet added)

LeetCode 269 - Alien Dictionary · Solution ¶

🔴 Hard — Topics: graph, topological_sort, dfs

📁 View Solution

🟡 LeetCode 207 - Course Schedule · Solution
🟡 LeetCode 210 - Course Schedule II · Solution
LeetCode 0953 (metadata not yet added)

LeetCode 271 - Encode and Decode Strings · Solution ¶

🟡 Medium — Topics: string, design

📁 View Solution

🔴 LeetCode 297 - Serialize and Deserialize Binary Tree · Solution
LeetCode 0394 (metadata not yet added)
LeetCode 0443 (metadata not yet added)

LeetCode 286 - Walls and Gates · Solution ¶

🟡 Medium — Topics: array, breadth_first_search, matrix

📁 View Solution

🟡 LeetCode 994 - Rotting Oranges · Solution
🟡 LeetCode 542 - 01 Matrix · Solution
LeetCode 1162 (metadata not yet added)

LeetCode 297 - Serialize and Deserialize Binary Tree · Solution ¶

🔴 Hard — Topics: string, tree, depth_first_search

📁 View Solution

LeetCode 0449 (metadata not yet added)
LeetCode 0652 (metadata not yet added)
LeetCode 0428 (metadata not yet added)

LeetCode 303 - Range Sum Query - Immutable · Solution ¶

🟢 Easy — Topics: array, design, prefix_sum

📁 View Solution

🟡 LeetCode 304 - Range Sum Query 2D - Immutable · Solution
🟡 LeetCode 307 - Range Sum Query - Mutable · Solution
🟡 LeetCode 560 - Subarray Sum Equals K · Solution

LeetCode 307 - Range Sum Query - Mutable · Solution ¶

🟡 Medium — Topics: array, design, binary_indexed_tree

📁 View Solution

🟢 LeetCode 303 - Range Sum Query - Immutable · Solution
🟡 LeetCode 304 - Range Sum Query 2D - Immutable · Solution
LeetCode 0308 (metadata not yet added)

LeetCode 329 - Longest Increasing Path in a Matrix · Solution ¶

🔴 Hard — Topics: array, dynamic_programming, dfs

📁 View Solution

🟡 LeetCode 200 - Number of Islands · Solution
🟡 LeetCode 417 - Pacific Atlantic Water Flow · Solution
🟡 LeetCode 695 - Max Area of Island · Solution

LeetCode 337 - House Robber III · Solution ¶

🟡 Medium — Topics: dynamic_programming, tree, depth_first_search

📁 View Solution

🟡 LeetCode 198 - House Robber · Solution
🟡 LeetCode 213 - House Robber II · Solution
🔴 LeetCode 124 - Binary Tree Maximum Path Sum · Solution

LeetCode 338 - Counting Bits · Solution ¶

🟢 Easy — Topics: dynamic_programming, bit_manipulation

📁 View Solution

🟢 LeetCode 191 - Number of 1 Bits · Solution
🟢 LeetCode 190 - Reverse Bits · Solution
LeetCode 0461 (metadata not yet added)

LeetCode 347 - Top K Frequent Elements · Solution ¶

🟡 Medium — Topics: array, hash_table, divide_and_conquer

📁 View Solution

🟡 LeetCode 215 - Kth Largest Element in an Array · Solution
LeetCode 0451 (metadata not yet added)
LeetCode 0692 (metadata not yet added)

LeetCode 355 - Design Twitter · Solution ¶

🟡 Medium — Topics: hash_table, linked_list, design

📁 View Solution

🔴 LeetCode 23 - Merge k Sorted Lists · Solution
🟡 LeetCode 146 - LRU Cache · Solution
LeetCode 0380 (metadata not yet added)

LeetCode 371 - Sum of Two Integers · Solution ¶

🟡 Medium — Topics: math, bit_manipulation

📁 View Solution

LeetCode 0067 (metadata not yet added)
LeetCode 0415 (metadata not yet added)
LeetCode 0989 (metadata not yet added)

LeetCode 402 - Remove K Digits · Solution ¶

🟡 Medium — Topics: string, stack, greedy

📁 View Solution

🟡 LeetCode 316 - Remove Duplicate Letters · Solution
🔴 LeetCode 321 - Create Maximum Number · Solution
LeetCode 0738 (metadata not yet added)

LeetCode 417 - Pacific Atlantic Water Flow · Solution ¶

🟡 Medium — Topics: array, depth_first_search, breadth_first_search

📁 View Solution

🟡 LeetCode 200 - Number of Islands · Solution
🟡 LeetCode 130 - Surrounded Regions · Solution
🔴 LeetCode 329 - Longest Increasing Path in a Matrix · Solution

LeetCode 424 - Longest Repeating Character Replacement · Solution ¶

🟡 Medium — Topics: hash_table, string, sliding_window

📁 View Solution

LeetCode 435 - Non-overlapping Intervals · Solution ¶

🟡 Medium — Topics: array, dynamic_programming, greedy

📁 View Solution

🟡 LeetCode 452 - Minimum Number of Arrows to Burst Balloons · Solution
LeetCode 0646 (metadata not yet added)
LeetCode 1235 (metadata not yet added)

LeetCode 452 - Minimum Number of Arrows to Burst Balloons · Solution ¶

🟡 Medium — Topics: array, greedy, sorting

📁 View Solution

🟡 LeetCode 435 - Non-overlapping Intervals · Solution
🟡 LeetCode 253 - Meeting Rooms II · Solution
🟡 LeetCode 56 - Merge Intervals · Solution

LeetCode 496 - Next Greater Element I · Solution ¶

🟢 Easy — Topics: array, hash_table, stack

📁 View Solution

🟡 LeetCode 503 - Next Greater Element II · Solution
LeetCode 0556 (metadata not yet added)
🟡 LeetCode 739 - Daily Temperatures · Solution

LeetCode 523 - Continuous Subarray Sum · Solution ¶

🟡 Medium — Topics: array, hash_table, math

📁 View Solution

🟡 LeetCode 560 - Subarray Sum Equals K · Solution
🟡 LeetCode 525 - Contiguous Array · Solution
LeetCode 0974 (metadata not yet added)

LeetCode 525 - Contiguous Array · Solution ¶

🟡 Medium — Topics: array, hash_table, prefix_sum

📁 View Solution

🟡 LeetCode 560 - Subarray Sum Equals K · Solution
🟡 LeetCode 523 - Continuous Subarray Sum · Solution
LeetCode 0930 (metadata not yet added)

LeetCode 542 - 01 Matrix · Solution ¶

🟡 Medium — Topics: array, dynamic_programming, breadth_first_search

📁 View Solution

🟡 LeetCode 994 - Rotting Oranges · Solution
🟡 LeetCode 286 - Walls and Gates · Solution
LeetCode 1162 (metadata not yet added)

LeetCode 547 - Number of Provinces · Solution ¶

🟡 Medium — Topics: depth_first_search, breadth_first_search, union_find

📁 View Solution

🟡 LeetCode 200 - Number of Islands · Solution
LeetCode 0323 (metadata not yet added)
🟡 LeetCode 1319 - Number of Operations to Make Network Connected · Solution

LeetCode 572 - Subtree of Another Tree · Solution ¶

🟢 Easy — Topics: tree, depth_first_search, string_matching

📁 View Solution

🟢 LeetCode 100 - Same Tree · Solution
🟢 LeetCode 226 - Invert Binary Tree · Solution
LeetCode 0508 (metadata not yet added)

LeetCode 621 - Task Scheduler · Solution ¶

🟡 Medium — Topics: array, hash_table, greedy

📁 View Solution

LeetCode 0767 (metadata not yet added)
LeetCode 0358 (metadata not yet added)
LeetCode 1834 (metadata not yet added)

LeetCode 647 - Palindromic Substrings · Solution ¶

🟡 Medium — Topics: two_pointers, string, dynamic_programming

📁 View Solution

🟡 LeetCode 5 - Longest Palindromic Substring · Solution
🟡 LeetCode 516 - Longest Palindromic Subsequence · Solution
🟡 LeetCode 131 - Palindrome Partitioning · Solution

LeetCode 678 - Valid Parenthesis String · Solution ¶

🟡 Medium — Topics: string, dynamic_programming, stack

📁 View Solution

🟢 LeetCode 20 - Valid Parentheses · Solution
🟡 LeetCode 22 - Generate Parentheses · Solution
LeetCode 0032 (metadata not yet added)

LeetCode 695 - Max Area of Island · Solution ¶

🟡 Medium — Topics: array, depth_first_search, breadth_first_search

📁 View Solution

🟡 LeetCode 200 - Number of Islands · Solution
LeetCode 0463 (metadata not yet added)
LeetCode 0733 (metadata not yet added)

LeetCode 703 - Kth Largest Element in a Stream · Solution ¶

🟢 Easy — Topics: tree, design, binary_search_tree

📁 View Solution

🟡 LeetCode 215 - Kth Largest Element in an Array · Solution
🟡 LeetCode 347 - Top K Frequent Elements · Solution
🔴 LeetCode 295 - Find Median from Data Stream · Solution

LeetCode 704 - Binary Search · Solution ¶

🟢 Easy — Topics: array, binary_search

📁 View Solution

🟡 LeetCode 33 - Search in Rotated Sorted Array · Solution
🟡 LeetCode 34 - Find First and Last Position of Element in Sorted Array · Solution
🟢 LeetCode 35 - Search Insert Position · Solution

LeetCode 707 - Design Linked List · Solution ¶

🟡 Medium — Topics: linked-list, design

📁 View Solution

🟡 LeetCode 146 - LRU Cache · Solution
LeetCode 0460 (metadata not yet added)
LeetCode 0706 (metadata not yet added)

LeetCode 721 - Accounts Merge · Solution ¶

🟡 Medium — Topics: array, string, depth_first_search

📁 View Solution

🟡 LeetCode 990 - Satisfiability of Equality Equations · Solution
LeetCode 0839 (metadata not yet added)
LeetCode 1202 (metadata not yet added)

LeetCode 763 - Partition Labels · Solution ¶

🟡 Medium — Topics: hash_table, two_pointers, string

📁 View Solution

🟡 LeetCode 56 - Merge Intervals · Solution
🟡 LeetCode 435 - Non-overlapping Intervals · Solution
🟡 LeetCode 452 - Minimum Number of Arrows to Burst Balloons · Solution

LeetCode 802 - Find Eventual Safe States · Solution ¶

🟡 Medium — Topics: depth_first_search, breadth_first_search, graph

📁 View Solution

🟡 LeetCode 207 - Course Schedule · Solution
🟡 LeetCode 210 - Course Schedule II · Solution
🔴 LeetCode 1203 - Sort Items by Groups Respecting Dependencies · Solution

LeetCode 846 - Hand of Straights · Solution ¶

🟡 Medium — Topics: array, hash_table, greedy

📁 View Solution

LeetCode 1296 (metadata not yet added)
LeetCode 0659 (metadata not yet added)
LeetCode 2009 (metadata not yet added)

LeetCode 853 - Car Fleet · Solution ¶

🟡 Medium — Topics: array, stack, sorting

📁 View Solution

🟡 LeetCode 739 - Daily Temperatures · Solution
🟡 LeetCode 901 - Online Stock Span · Solution
LeetCode 1776 (metadata not yet added)

LeetCode 973 - K Closest Points to Origin · Solution ¶

🟡 Medium — Topics: array, math, divide_and_conquer

📁 View Solution

🟡 LeetCode 215 - Kth Largest Element in an Array · Solution
🟡 LeetCode 347 - Top K Frequent Elements · Solution
LeetCode 0692 (metadata not yet added)

LeetCode 981 - Time Based Key-Value Store · Solution ¶

🟡 Medium — Topics: hash_table, string, binary_search

📁 View Solution

🟡 LeetCode 146 - LRU Cache · Solution
LeetCode 0380 (metadata not yet added)
LeetCode 0705 (metadata not yet added)

LeetCode 986 - Interval List Intersections · Solution ¶

🟡 Medium — Topics: array, two_pointers

📁 View Solution

🟡 LeetCode 56 - Merge Intervals · Solution
🟢 LeetCode 88 - Merge Sorted Array · Solution
LeetCode 0349 (metadata not yet added)

LeetCode 990 - Satisfiability of Equality Equations · Solution ¶

🟡 Medium — Topics: array, string, union_find

📁 View Solution

🟡 LeetCode 721 - Accounts Merge · Solution
LeetCode 0399 (metadata not yet added)
LeetCode 1061 (metadata not yet added)

LeetCode 1203 - Sort Items by Groups Respecting Dependencies · Solution ¶

🔴 Hard — Topics: depth_first_search, breadth_first_search, graph

📁 View Solution

🟡 LeetCode 207 - Course Schedule · Solution
🟡 LeetCode 210 - Course Schedule II · Solution
🟡 LeetCode 802 - Find Eventual Safe States · Solution

LeetCode 1319 - Number of Operations to Make Network Connected · Solution ¶

🟡 Medium — Topics: depth_first_search, breadth_first_search, union_find

📁 View Solution

🟡 LeetCode 547 - Number of Provinces · Solution
LeetCode 1579 (metadata not yet added)
LeetCode 1101 (metadata not yet added)

LeetCode 1438 - Longest Continuous Subarray With Absolute Diff Less Than or Equal to Limit · Solution ¶

🟡 Medium — Topics: array, queue, sliding_window

📁 View Solution

🔴 LeetCode 239 - Sliding Window Maximum · Solution
🔴 LeetCode 862 - Shortest Subarray with Sum at Least K · Solution
🔴 LeetCode 1499 - Max Value of Equation · Solution

LeetCode 1499 - Max Value of Equation · Solution ¶

🔴 Hard — Topics: array, queue, sliding_window

📁 View Solution

LeetCode 1899 - Merge Triplets to Form Target Triplet · Solution ¶

🟡 Medium — Topics: array, greedy

📁 View Solution

LeetCode 1923 - Longest Common Subpath · Solution ¶

🔴 Hard — Topics: array, binary-search, rolling-hash

📁 View Solution

LeetCode 0718 (metadata not yet added)
LeetCode 1062 (metadata not yet added)
LeetCode 1044 (metadata not yet added)

LeetCode 1971 - Find if Path Exists in Graph · Solution ¶

🟢 Easy — Topics: depth_first_search, breadth_first_search, union_find

📁 View Solution

🟡 LeetCode 547 - Number of Provinces · Solution
🟡 LeetCode 684 - Redundant Connection · Solution
🟡 LeetCode 841 - Keys and Rooms · Solution

LeetCode 2407 - Longest Increasing Subsequence II · Solution ¶

🔴 Hard — Topics: array, dynamic_programming, segment_tree

📁 View Solution

🟡 LeetCode 300 - Longest Increasing Subsequence · Solution
LeetCode 0673 (metadata not yet added)
LeetCode 0354 (metadata not yet added)

LeetCode 10 - Regular Expression Matching · Solution ¶

🔴 Hard — Topics: String, Dynamic Programming, Recursion

📁 View Solution

🔴 LeetCode 44 - Wildcard Matching
🟡 LeetCode 1143 - Longest Common Subsequence · Solution

LeetCode 16 - 3Sum Closest · Solution ¶

🟡 Medium — Topics: array, two_pointers, sorting

📁 View Solution

🟡 LeetCode 15 - 3Sum · Solution
🟢 LeetCode 1 - Two Sum · Solution

LeetCode 27 - Remove Element · Solution ¶

🟢 Easy — Topics: array, two_pointers

📁 View Solution

🟢 LeetCode 26 - Remove Duplicates from Sorted Array · Solution
🟢 LeetCode 283 - Move Zeroes · Solution

LeetCode 49 - Group Anagrams · Solution ¶

🟡 Medium — Topics: array, hash_table, string

📁 View Solution

🟢 LeetCode 242 - Valid Anagram · Solution
🟡 LeetCode 438 - Find All Anagrams in a String · Solution

LeetCode 50 - Pow(x, n) · Solution(x, n)¶

🟡 Medium — Topics: math, recursion

📁 View Solution

LeetCode 0069 (metadata not yet added)
LeetCode 0372 (metadata not yet added)

LeetCode 51 - N-Queens · Solution ¶

🔴 Hard — Topics: array, backtracking

📁 View Solution

🔴 LeetCode 52 - N-Queens II · Solution
LeetCode 0037 (metadata not yet added)

LeetCode 55 - Jump Game · Solution ¶

🟡 Medium — Topics: array, dynamic_programming, greedy

📁 View Solution

🟡 LeetCode 45 - Jump Game II · Solution
🟡 LeetCode 134 - Gas Station · Solution

LeetCode 70 - Climbing Stairs · Solution ¶

🟢 Easy — Topics: math, dynamic_programming, memoization

📁 View Solution

🟢 LeetCode 746 - Min Cost Climbing Stairs · Solution
🟡 LeetCode 198 - House Robber · Solution

LeetCode 74 - Search a 2D Matrix · Solution ¶

🟡 Medium — Topics: array, binary_search, matrix

📁 View Solution

LeetCode 0240 (metadata not yet added)
🟢 LeetCode 35 - Search Insert Position · Solution

LeetCode 75 - Sort Colors · Solution ¶

🟡 Medium — Topics: array, two_pointers, sorting

📁 View Solution

🟢 LeetCode 905 - Sort Array By Parity · Solution
🟢 LeetCode 922 - Sort Array By Parity II · Solution

LeetCode 80 - Remove Duplicates from Sorted Array II · Solution ¶

🟡 Medium — Topics: array, two_pointers

📁 View Solution

🟢 LeetCode 26 - Remove Duplicates from Sorted Array · Solution
🟢 LeetCode 27 - Remove Element · Solution

LeetCode 84 - Largest Rectangle in Histogram · Solution ¶

🔴 Hard — Topics: array, stack, monotonic_stack

📁 View Solution

🔴 LeetCode 85 - Maximal Rectangle · Solution
🔴 LeetCode 42 - Trapping Rain Water · Solution

LeetCode 85 - Maximal Rectangle · Solution ¶

🔴 Hard — Topics: array, dynamic_programming, stack

📁 View Solution

🔴 LeetCode 84 - Largest Rectangle in Histogram · Solution
LeetCode 0221 (metadata not yet added)

LeetCode 88 - Merge Sorted Array · Solution ¶

🟢 Easy — Topics: array, two_pointers, sorting

📁 View Solution

🟢 LeetCode 21 - Merge Two Sorted Lists · Solution
🟢 LeetCode 977 - Squares of a Sorted Array · Solution

LeetCode 92 - Reverse Linked List II · Solution ¶

🟡 Medium — Topics: linked_list

📁 View Solution

🟢 LeetCode 206 - Reverse Linked List · Solution
🔴 LeetCode 25 - Reverse Nodes in k-Group · Solution

LeetCode 93 - Restore IP Addresses · Solution ¶

🟡 Medium — Topics: string, backtracking

📁 View Solution

🟡 LeetCode 131 - Palindrome Partitioning · Solution
🟡 LeetCode 93 - Restore IP Addresses · Solution

LeetCode 105 - Construct Binary Tree from Preorder and Inorder Traversal · Solution ¶

🟡 Medium — Topics: array, hash_table, divide_and_conquer

📁 View Solution

LeetCode 0106 (metadata not yet added)
LeetCode 0889 (metadata not yet added)

LeetCode 121 - Best Time to Buy and Sell Stock · Solution ¶

🟢 Easy — Topics: array, dynamic_programming

📁 View Solution

🟡 LeetCode 53 - Maximum Subarray · Solution
LeetCode 0122 (metadata not yet added)

LeetCode 128 - Longest Consecutive Sequence · Solution ¶

🟡 Medium — Topics: array, hash_table, union_find

📁 View Solution

LeetCode 0298 (metadata not yet added)
LeetCode 0549 (metadata not yet added)

LeetCode 131 - Palindrome Partitioning · Solution ¶

🟡 Medium — Topics: string, dynamic_programming, backtracking

📁 View Solution

🟡 LeetCode 93 - Restore IP Addresses · Solution
🟡 LeetCode 5 - Longest Palindromic Substring · Solution

LeetCode 133 - Clone Graph · Solution ¶

🟡 Medium — Topics: hash_table, depth_first_search, breadth_first_search

📁 View Solution

🟡 LeetCode 138 - Copy List with Random Pointer · Solution
LeetCode 1485 (metadata not yet added)

LeetCode 134 - Gas Station · Solution ¶

🟡 Medium — Topics: array, greedy

📁 View Solution

🟡 LeetCode 55 - Jump Game · Solution
🟡 LeetCode 45 - Jump Game II · Solution

LeetCode 138 - Copy List with Random Pointer · Solution ¶

🟡 Medium — Topics: hash_table, linked_list

📁 View Solution

🟡 LeetCode 133 - Clone Graph · Solution
LeetCode 1485 (metadata not yet added)

LeetCode 139 - Word Break · Solution ¶

🟡 Medium — Topics: array, hash_table, string

📁 View Solution

LeetCode 0140 (metadata not yet added)
LeetCode 0472 (metadata not yet added)

LeetCode 141 - Linked List Cycle · Solution ¶

🟢 Easy — Topics: linked_list, two_pointers, hash_table

📁 View Solution

🟡 LeetCode 142 - Linked List Cycle II · Solution
🟢 LeetCode 202 - Happy Number · Solution

LeetCode 142 - Linked List Cycle II · Solution ¶

🟡 Medium — Topics: linked_list, two_pointers, hash_table

📁 View Solution

🟢 LeetCode 141 - Linked List Cycle · Solution
🟢 LeetCode 202 - Happy Number · Solution

LeetCode 155 - Min Stack · Solution ¶

🟡 Medium — Topics: stack, design

📁 View Solution

🔴 LeetCode 239 - Sliding Window Maximum · Solution
LeetCode 0716 (metadata not yet added)

LeetCode 198 - House Robber · Solution ¶

🟡 Medium — Topics: array, dynamic_programming

📁 View Solution

🟡 LeetCode 213 - House Robber II · Solution
🟢 LeetCode 70 - Climbing Stairs · Solution

LeetCode 202 - Happy Number · Solution ¶

🟢 Easy — Topics: hash_table, math, two_pointers

📁 View Solution

🟢 LeetCode 141 - Linked List Cycle · Solution
🟡 LeetCode 142 - Linked List Cycle II · Solution

LeetCode 204 - Count Primes · Solution ¶

🟡 Medium — Topics: array, math, enumeration

📁 View Solution

🟢 LeetCode 1979 - Find Greatest Common Divisor of Array · Solution
🟢 LeetCode 168 - Excel Sheet Column Title · Solution

LeetCode 215 - Kth Largest Element in an Array · Solution ¶

🟡 Medium — Topics: array, divide_and_conquer, sorting

📁 View Solution

🟡 LeetCode 347 - Top K Frequent Elements · Solution
LeetCode 0378 (metadata not yet added)

LeetCode 218 - The Skyline Problem · Solution ¶

🔴 Hard — Topics: array, divide_and_conquer, binary_indexed_tree

📁 View Solution

🟡 LeetCode 253 - Meeting Rooms II · Solution
🟡 LeetCode 1094 - Car Pooling · Solution

LeetCode 220 - Contains Duplicate III · Solution ¶

🔴 Hard — Topics: array, sliding_window, sorting

📁 View Solution

🟢 LeetCode 217 - Contains Duplicate · Solution
LeetCode 0219 (metadata not yet added)

LeetCode 238 - Product of Array Except Self · Solution ¶

🟡 Medium — Topics: array, prefix_sum

📁 View Solution

🔴 LeetCode 42 - Trapping Rain Water · Solution
🟡 LeetCode 152 - Maximum Product Subarray · Solution

LeetCode 283 - Move Zeroes · Solution ¶

🟢 Easy — Topics: array, two_pointers

📁 View Solution

🟢 LeetCode 27 - Remove Element · Solution
🟢 LeetCode 26 - Remove Duplicates from Sorted Array · Solution

LeetCode 295 - Find Median from Data Stream · Solution ¶

🔴 Hard — Topics: two_pointers, design, sorting

📁 View Solution

LeetCode 0480 (metadata not yet added)
🟢 LeetCode 703 - Kth Largest Element in a Stream · Solution

LeetCode 304 - Range Sum Query 2D - Immutable · Solution ¶

🟡 Medium — Topics: array, design, matrix

📁 View Solution

🟢 LeetCode 303 - Range Sum Query - Immutable · Solution
LeetCode 0308 (metadata not yet added)

LeetCode 315 - Count of Smaller Numbers After Self · Solution ¶

🔴 Hard — Topics: array, binary_search, divide_and_conquer

📁 View Solution

🔴 LeetCode 327 - Count of Range Sum · Solution
LeetCode 0493 (metadata not yet added)

LeetCode 316 - Remove Duplicate Letters · Solution ¶

🟡 Medium — Topics: string, stack, greedy

📁 View Solution

🟡 LeetCode 402 - Remove K Digits · Solution
LeetCode 1081 (metadata not yet added)

LeetCode 321 - Create Maximum Number · Solution ¶

🔴 Hard — Topics: array, two_pointers, stack

📁 View Solution

🟡 LeetCode 402 - Remove K Digits · Solution
🟡 LeetCode 316 - Remove Duplicate Letters · Solution

LeetCode 322 - Coin Change · Solution ¶

🟡 Medium — Topics: array, dynamic_programming, bfs

📁 View Solution

🟡 LeetCode 518 - Coin Change II · Solution
LeetCode 0279 (metadata not yet added)

LeetCode 327 - Count of Range Sum · Solution ¶

🔴 Hard — Topics: array, binary_search, divide_and_conquer

📁 View Solution

🔴 LeetCode 315 - Count of Smaller Numbers After Self · Solution
LeetCode 0493 (metadata not yet added)

LeetCode 332 - Reconstruct Itinerary · Solution ¶

🔴 Hard — Topics: dfs, graph, eulerian_circuit

📁 View Solution

LeetCode 0753 (metadata not yet added)
LeetCode 2097 (metadata not yet added)

LeetCode 416 - Partition Equal Subset Sum · Solution ¶

🟡 Medium — Topics: array, dynamic_programming

📁 View Solution

🟡 LeetCode 494 - Target Sum · Solution
LeetCode 0698 (metadata not yet added)

LeetCode 420 - Strong Password Checker · Solution ¶

🔴 Hard — Topics: string, greedy, heap

📁 View Solution

LeetCode 0068 (metadata not yet added)
LeetCode 0068 (metadata not yet added)

LeetCode 503 - Next Greater Element II · Solution ¶

🟡 Medium — Topics: array, stack, monotonic_stack

📁 View Solution

🟢 LeetCode 496 - Next Greater Element I · Solution
LeetCode 0556 (metadata not yet added)

LeetCode 518 - Coin Change II · Solution ¶

🟡 Medium — Topics: array, dynamic_programming

📁 View Solution

🟡 LeetCode 322 - Coin Change · Solution
LeetCode 0377 (metadata not yet added)

LeetCode 665 - Non-decreasing Array · Solution ¶

🟡 Medium — Topics: array, greedy

📁 View Solution

🟡 LeetCode 53 - Maximum Subarray · Solution
🟢 LeetCode 283 - Move Zeroes · Solution

LeetCode 684 - Redundant Connection · Solution ¶

🟡 Medium — Topics: depth_first_search, breadth_first_search, union_find

📁 View Solution

LeetCode 0685 (metadata not yet added)
🟡 LeetCode 261 - Graph Valid Tree · Solution

LeetCode 739 - Daily Temperatures · Solution ¶

🟡 Medium — Topics: array, stack, monotonic_stack

📁 View Solution

🟢 LeetCode 496 - Next Greater Element I · Solution
🟡 LeetCode 901 - Online Stock Span · Solution

LeetCode 805 - Split Array With Same Average · Solution ¶

🔴 Hard — Topics: array, math, dynamic_programming

📁 View Solution

🟡 LeetCode 416 - Partition Equal Subset Sum · Solution
🟡 LeetCode 494 - Target Sum · Solution

LeetCode 841 - Keys and Rooms · Solution ¶

🟡 Medium — Topics: depth_first_search, breadth_first_search, graph

📁 View Solution

🟡 LeetCode 547 - Number of Provinces · Solution
🟢 LeetCode 1971 - Find if Path Exists in Graph · Solution

LeetCode 847 - Shortest Path Visiting All Nodes · Solution ¶

🔴 Hard — Topics: dynamic_programming, bit_manipulation, bfs

📁 View Solution

LeetCode 0943 (metadata not yet added)
🔴 LeetCode 1494 - Parallel Courses II

LeetCode 876 - Middle of the Linked List · Solution ¶

🟢 Easy — Topics: linked_list, two_pointers

📁 View Solution

🟢 LeetCode 141 - Linked List Cycle · Solution
🟡 LeetCode 142 - Linked List Cycle II · Solution

LeetCode 901 - Online Stock Span · Solution ¶

🟡 Medium — Topics: stack, design, monotonic_stack

📁 View Solution

🟡 LeetCode 739 - Daily Temperatures · Solution
🟢 LeetCode 496 - Next Greater Element I · Solution

LeetCode 905 - Sort Array By Parity · Solution ¶

🟢 Easy — Topics: array, two_pointers, sorting

📁 View Solution

🟡 LeetCode 75 - Sort Colors · Solution
🟢 LeetCode 922 - Sort Array By Parity II · Solution

LeetCode 907 - Sum of Subarray Minimums · Solution ¶

🟡 Medium — Topics: array, dynamic_programming, stack

📁 View Solution

🟡 LeetCode 2104 - Sum of Subarray Ranges · Solution
🔴 LeetCode 84 - Largest Rectangle in Histogram · Solution

LeetCode 922 - Sort Array By Parity II · Solution ¶

🟢 Easy — Topics: array, two_pointers

📁 View Solution

🟢 LeetCode 905 - Sort Array By Parity · Solution
🟡 LeetCode 75 - Sort Colors · Solution

LeetCode 968 - Binary Tree Cameras · Solution ¶

🔴 Hard — Topics: dynamic_programming, tree, depth_first_search

📁 View Solution

🟡 LeetCode 337 - House Robber III · Solution
🔴 LeetCode 124 - Binary Tree Maximum Path Sum · Solution

LeetCode 977 - Squares of a Sorted Array · Solution ¶

🟢 Easy — Topics: array, two_pointers, sorting

📁 View Solution

🟢 LeetCode 21 - Merge Two Sorted Lists · Solution
🟢 LeetCode 88 - Merge Sorted Array · Solution

LeetCode 1046 - Last Stone Weight · Solution ¶

🟢 Easy — Topics: array, heap

📁 View Solution

LeetCode 1049 (metadata not yet added)
LeetCode 1167 (metadata not yet added)

LeetCode 1094 - Car Pooling · Solution ¶

🟡 Medium — Topics: array, sorting, heap_priority_queue

📁 View Solution

🟡 LeetCode 1109 - Corporate Flight Bookings · Solution
🟡 LeetCode 253 - Meeting Rooms II · Solution

LeetCode 1109 - Corporate Flight Bookings · Solution ¶

🟡 Medium — Topics: array, prefix_sum

📁 View Solution

🟡 LeetCode 1094 - Car Pooling · Solution
LeetCode 0370 (metadata not yet added)

LeetCode 1125 - Smallest Sufficient Team · Solution ¶

🔴 Hard — Topics: array, dynamic_programming, bit_manipulation

📁 View Solution

LeetCode 1723 (metadata not yet added)
LeetCode 1986 (metadata not yet added)

LeetCode 1909 - Remove One Element to Make the Array Strictly Increasing · Solution ¶

🟢 Easy — Topics: array

📁 View Solution

🟡 LeetCode 665 - Non-decreasing Array · Solution
LeetCode 0376 (metadata not yet added)

LeetCode 1979 - Find Greatest Common Divisor of Array · Solution ¶

🟢 Easy — Topics: array, math, number_theory

📁 View Solution

🟡 LeetCode 204 - Count Primes · Solution
🟢 LeetCode 168 - Excel Sheet Column Title · Solution

LeetCode 2013 - Detect Squares · Solution ¶

🟡 Medium — Topics: array, hash_table, design

📁 View Solution

🔴 LeetCode 149 - Max Points on a Line · Solution
LeetCode 0593 (metadata not yet added)

LeetCode 2104 - Sum of Subarray Ranges · Solution ¶

🟡 Medium — Topics: array, stack, monotonic_stack

📁 View Solution

🟡 LeetCode 907 - Sum of Subarray Minimums · Solution
🔴 LeetCode 84 - Largest Rectangle in Histogram · Solution

LeetCode 2156 - Find Substring With Given Hash Value · Solution ¶

🔴 Hard — Topics: string, sliding_window, rolling_hash

📁 View Solution

🟢 LeetCode 28 - Find the Index of the First Occurrence in a String
LeetCode 0187 (metadata not yet added)

LeetCode 2332 - The Latest Time to Catch a Bus · Solution ¶

🟡 Medium — Topics: array, two-pointers, binary-search

📁 View Solution

LeetCode 1870 (metadata not yet added)
LeetCode 2410 (metadata not yet added)

LeetCode 2550 - Count Collisions of Monkeys on a Polygon · Solution ¶

🟡 Medium — Topics: math, recursion

📁 View Solution

🟡 LeetCode 50 - Pow(x, n) · Solution(x, n)
LeetCode 0372 (metadata not yet added)

LeetCode 2572 - Count the Number of Square-Free Subsets · Solution ¶

🟡 Medium — Topics: array, math, dynamic_programming

📁 View Solution

🟡 LeetCode 78 - Subsets · Solution
🟡 LeetCode 90 - Subsets II · Solution

LeetCode 2708 - Maximum Strength of a Group · Solution ¶

🟡 Medium — Topics: array, greedy, sorting

📁 View Solution

🟡 LeetCode 152 - Maximum Product Subarray · Solution
LeetCode 0628 (metadata not yet added)

LeetCode 8 - String to Integer (atoi) · Solution(atoi)¶

🟡 Medium — Topics: string

📁 View Solution

🟡 LeetCode 7 - Reverse Integer · Solution

LeetCode 36 - Valid Sudoku · Solution ¶

🟡 Medium — Topics: array, hash_table, matrix

📁 View Solution

LeetCode 0037 (metadata not yet added)

LeetCode 44 - Wildcard Matching ¶

🔴 Hard — Topics: string, dynamic_programming, greedy

📁 View Solution

🔴 LeetCode 10 - Regular Expression Matching · Solution

LeetCode 45 - Jump Game II · Solution ¶

🟡 Medium — Topics: array, dynamic_programming, greedy

📁 View Solution

🟡 LeetCode 55 - Jump Game · Solution

LeetCode 52 - N-Queens II · Solution ¶

🔴 Hard — Topics: backtracking

📁 View Solution

🔴 LeetCode 51 - N-Queens · Solution

LeetCode 65 - Valid Number · Solution ¶

🔴 Hard — Topics: string

📁 View Solution

🟡 LeetCode 8 - String to Integer (atoi) · Solution(atoi)

LeetCode 73 - Set Matrix Zeroes · Solution ¶

🟡 Medium — Topics: array, hash_table, matrix

📁 View Solution

LeetCode 0289 (metadata not yet added)

LeetCode 126 - Word Ladder II · Solution ¶

🔴 Hard — Topics: hash_table, string, backtracking

📁 View Solution

-LeetCode 127 - Word Ladder · Solution (metadata not yet added)

LeetCode 135 - Candy · Solution ¶

🔴 Hard — Topics: array, greedy

📁 View Solution

🟢 LeetCode 455 - Assign Cookies · Solution

LeetCode 149 - Max Points on a Line · Solution ¶

🔴 Hard — Topics: array, hash-table, math

📁 View Solution

LeetCode 0356 (metadata not yet added)

LeetCode 168 - Excel Sheet Column Title · Solution ¶

🟢 Easy — Topics: math, string

📁 View Solution

LeetCode 0171 (metadata not yet added)

LeetCode 213 - House Robber II · Solution ¶

🟡 Medium — Topics: array, dynamic_programming

📁 View Solution

🟡 LeetCode 198 - House Robber · Solution

LeetCode 455 - Assign Cookies · Solution ¶

🟢 Easy — Topics: array, two_pointers, greedy

📁 View Solution

🟡 LeetCode 1029 - Two City Scheduling · Solution

LeetCode 494 - Target Sum · Solution ¶

🟡 Medium — Topics: array, dynamic_programming, backtracking

📁 View Solution

🟡 LeetCode 416 - Partition Equal Subset Sum · Solution

LeetCode 680 - Valid Palindrome II · Solution ¶

🟢 Easy — Topics: two_pointers, string, greedy

📁 View Solution

🟢 LeetCode 125 - Valid Palindrome · Solution

LeetCode 746 - Min Cost Climbing Stairs · Solution ¶

🟢 Easy — Topics: array, dynamic_programming

📁 View Solution

🟢 LeetCode 70 - Climbing Stairs · Solution

LeetCode 785 - Is Graph Bipartite? · Solution ¶

🟡 Medium — Topics: depth_first_search, breadth_first_search, union_find

📁 View Solution

LeetCode 0886 (metadata not yet added)

LeetCode 887 - Super Egg Drop · Solution ¶

🔴 Hard — Topics: math, binary-search, dynamic-programming

📁 View Solution

LeetCode 1884 (metadata not yet added)

LeetCode 1029 - Two City Scheduling · Solution ¶

🟡 Medium — Topics: array, greedy, sorting

📁 View Solution

🟢 LeetCode 455 - Assign Cookies · Solution

LeetCode 1191 - K-Concatenation Maximum Sum · Solution ¶

🟡 Medium — Topics: array, dynamic_programming

📁 View Solution

🟡 LeetCode 53 - Maximum Subarray · Solution

LeetCode 1648 - Sell Diminishing-Valued Colored Balls · Solution ¶

🟡 Medium — Topics: array, math, binary-search

📁 View Solution

LeetCode 1870 (metadata not yet added)

LeetCode 2035 - Partition Array Into Two Arrays to Minimize Sum Difference · Solution ¶

🔴 Hard — Topics: array, two_pointers, binary_search

📁 View Solution

🟡 LeetCode 416 - Partition Equal Subset Sum · Solution

LeetCode 2069 - Walking Robot Simulation II · Solution ¶

🟡 Medium — Topics: design, simulation, math

📁 View Solution

LeetCode 0874 (metadata not yet added)

LeetCode 2280 - Minimum Lines to Represent a Line Chart · Solution ¶

🟡 Medium — Topics: array, math, geometry

📁 View Solution

🔴 LeetCode 149 - Max Points on a Line · Solution

LeetCode 2281 - Sum of Total Strength of Wizards · Solution ¶

🔴 Hard — Topics: array, stack, monotonic_stack

📁 View Solution

-LeetCode 907 - Sum of Subarray Minimums · Solution (metadata not yet added)

LeetCode 2286 - Booking Concert Tickets in Groups · Solution ¶

🔴 Hard — Topics: binary_search, design, segment_tree

📁 View Solution

🟡 LeetCode 307 - Range Sum Query - Mutable · Solution

LeetCode 2333 - Minimum Sum of Squared Difference · Solution ¶

🟡 Medium — Topics: array, math, sorting

📁 View Solution

LeetCode 0462 (metadata not yet added)

LeetCode 2659 - Make Array Empty · Solution ¶

🔴 Hard — Topics: array, sorting, greedy

📁 View Solution

🟡 LeetCode 621 - Task Scheduler · Solution

LeetCode 2736 - Maximum Sum Queries · Solution ¶

🔴 Hard — Topics: array, binary-search, stack

📁 View Solution

LeetCode 2940 (metadata not yet added)

Problem Relations Network¶

LeetCode 3 - Longest Substring Without Repeating Characters · Solution¶

Related Problems¶

LeetCode 19 - Remove Nth Node From End of List · Solution¶

Related Problems¶

LeetCode 994 - Rotting Oranges · Solution¶

Related Problems¶

LeetCode 2 - Add Two Numbers · Solution¶

Related Problems¶

LeetCode 17 - Letter Combinations of a Phone Number · Solution¶

Related Problems¶

LeetCode 76 - Minimum Window Substring · Solution¶

Related Problems¶

LeetCode 200 - Number of Islands · Solution¶

Related Problems¶

LeetCode 209 - Minimum Size Subarray Sum · Solution¶

Related Problems¶

LeetCode 340 - Longest Substring with At Most K Distinct Characters · Solution¶

Related Problems¶

LeetCode 2029 - Stone Game IX · Solution¶

Related Problems¶

LeetCode 1 - Two Sum · Solution¶

Related Problems¶

LeetCode 5 - Longest Palindromic Substring · Solution¶

Related Problems¶

LeetCode 15 - 3Sum · Solution¶

Related Problems¶

LeetCode 20 - Valid Parentheses · Solution¶

Related Problems¶

LeetCode 23 - Merge k Sorted Lists · Solution¶

Related Problems¶

LeetCode 33 - Search in Rotated Sorted Array · Solution¶

Related Problems¶

LeetCode 39 - Combination Sum · Solution¶

Related Problems¶

LeetCode 40 - Combination Sum II · Solution¶

Related Problems¶

LeetCode 56 - Merge Intervals · Solution¶

Related Problems¶

LeetCode 72 - Edit Distance · Solution¶

Related Problems¶

LeetCode 102 - Binary Tree Level Order Traversal · Solution¶

Related Problems¶

LeetCode 115 - Distinct Subsequences · Solution¶

Related Problems¶

LeetCode 124 - Binary Tree Maximum Path Sum · Solution¶

Related Problems¶

LeetCode 208 - Implement Trie (Prefix Tree) · Solution(Prefix Tree)¶

Related Problems¶

LeetCode 211 - Design Add and Search Words Data Structure · Solution¶

Related Problems¶

LeetCode 253 - Meeting Rooms II · Solution¶

Related Problems¶

LeetCode 300 - Longest Increasing Subsequence · Solution¶

Related Problems¶

LeetCode 309 - Best Time to Buy and Sell Stock with Cooldown · Solution¶

Related Problems¶

LeetCode 438 - Find All Anagrams in a String · Solution¶

Related Problems¶

LeetCode 516 - Longest Palindromic Subsequence · Solution¶

Related Problems¶

LeetCode 543 - Diameter of Binary Tree · Solution¶

Related Problems¶

LeetCode 560 - Subarray Sum Equals K · Solution¶

Related Problems¶

LeetCode 567 - Permutation in String · Solution¶

Related Problems¶

LeetCode 648 - Replace Words · Solution¶

Related Problems¶

LeetCode 743 - Network Delay Time · Solution¶

Related Problems¶

LeetCode 778 - Swim in Rising Water · Solution¶

Related Problems¶

LeetCode 787 - Cheapest Flights Within K Stops · Solution¶

Related Problems¶

LeetCode 862 - Shortest Subarray with Sum at Least K · Solution¶

Related Problems¶

LeetCode 875 - Koko Eating Bananas · Solution¶

Related Problems¶

LeetCode 1011 - Capacity To Ship Packages Within D Days · Solution¶

LeetCode 3 - Longest Substring Without Repeating Characters · Solution ¶

LeetCode 19 - Remove Nth Node From End of List · Solution ¶

LeetCode 994 - Rotting Oranges · Solution ¶

LeetCode 2 - Add Two Numbers · Solution ¶

LeetCode 17 - Letter Combinations of a Phone Number · Solution ¶

LeetCode 76 - Minimum Window Substring · Solution ¶

LeetCode 200 - Number of Islands · Solution ¶

LeetCode 209 - Minimum Size Subarray Sum · Solution ¶

LeetCode 340 - Longest Substring with At Most K Distinct Characters · Solution ¶

LeetCode 2029 - Stone Game IX · Solution ¶

LeetCode 1 - Two Sum · Solution ¶

LeetCode 5 - Longest Palindromic Substring · Solution ¶

LeetCode 15 - 3Sum · Solution ¶

LeetCode 20 - Valid Parentheses · Solution ¶

LeetCode 23 - Merge k Sorted Lists · Solution ¶

LeetCode 33 - Search in Rotated Sorted Array · Solution ¶

LeetCode 39 - Combination Sum · Solution ¶

LeetCode 40 - Combination Sum II · Solution ¶

LeetCode 56 - Merge Intervals · Solution ¶

LeetCode 72 - Edit Distance · Solution ¶

LeetCode 102 - Binary Tree Level Order Traversal · Solution ¶

LeetCode 115 - Distinct Subsequences · Solution ¶

LeetCode 124 - Binary Tree Maximum Path Sum · Solution ¶

LeetCode 211 - Design Add and Search Words Data Structure · Solution ¶

LeetCode 253 - Meeting Rooms II · Solution ¶

LeetCode 300 - Longest Increasing Subsequence · Solution ¶

LeetCode 309 - Best Time to Buy and Sell Stock with Cooldown · Solution ¶

LeetCode 438 - Find All Anagrams in a String · Solution ¶

LeetCode 516 - Longest Palindromic Subsequence · Solution ¶

LeetCode 543 - Diameter of Binary Tree · Solution ¶

LeetCode 560 - Subarray Sum Equals K · Solution ¶

LeetCode 567 - Permutation in String · Solution ¶

LeetCode 648 - Replace Words · Solution ¶

LeetCode 743 - Network Delay Time · Solution ¶

LeetCode 778 - Swim in Rising Water · Solution ¶

LeetCode 787 - Cheapest Flights Within K Stops · Solution ¶

LeetCode 862 - Shortest Subarray with Sum at Least K · Solution ¶

LeetCode 875 - Koko Eating Bananas · Solution ¶

LeetCode 1011 - Capacity To Ship Packages Within D Days · Solution ¶

LeetCode 1143 - Longest Common Subsequence · Solution ¶

LeetCode 1268 - Search Suggestions System · Solution ¶

LeetCode 1368 - Minimum Cost to Make at Least One Valid Path in a Grid · Solution ¶

LeetCode 1448 - Count Good Nodes in Binary Tree · Solution ¶

LeetCode 1584 - Min Cost to Connect All Points · Solution ¶

LeetCode 1631 - Path With Minimum Effort · Solution ¶

LeetCode 1851 - Minimum Interval to Include Each Query · Solution ¶

LeetCode 1871 - Jump Game VII · Solution ¶

LeetCode 2290 - Minimum Obstacle Removal to Reach Corner · Solution ¶

LeetCode 2741 - Special Permutations · Solution ¶

LeetCode 4 - Median of Two Sorted Arrays · Solution ¶

LeetCode 7 - Reverse Integer · Solution ¶

LeetCode 11 - Container With Most Water · Solution ¶

LeetCode 21 - Merge Two Sorted Lists · Solution ¶

LeetCode 22 - Generate Parentheses · Solution ¶

LeetCode 25 - Reverse Nodes in k-Group · Solution ¶

LeetCode 26 - Remove Duplicates from Sorted Array · Solution ¶

LeetCode 31 - Next Permutation · Solution ¶

LeetCode 34 - Find First and Last Position of Element in Sorted Array · Solution ¶

LeetCode 35 - Search Insert Position · Solution ¶

LeetCode 42 - Trapping Rain Water · Solution ¶

LeetCode 43 - Multiply Strings · Solution ¶

LeetCode 46 - Permutations · Solution ¶

LeetCode 47 - Permutations II · Solution ¶

LeetCode 48 - Rotate Image · Solution ¶

LeetCode 53 - Maximum Subarray · Solution ¶

LeetCode 54 - Spiral Matrix · Solution ¶

LeetCode 57 - Insert Interval · Solution ¶

LeetCode 62 - Unique Paths · Solution ¶

LeetCode 66 - Plus One · Solution ¶

LeetCode 77 - Combinations · Solution ¶

LeetCode 78 - Subsets · Solution ¶

LeetCode 79 - Word Search · Solution ¶

LeetCode 81 - Search in Rotated Sorted Array II · Solution ¶

LeetCode 90 - Subsets II · Solution ¶