Id Title Solution Time Runtime Space Difficulty Catagory
0001 Two Sum C no 0ms O(n) Easy Array
0002 Add Two Numbers C no 32ms O(1) Medium Array
0003 Longest Substring Without Repeating Characters C no 18ms O(n) Medium Array
0004 Median of Two Sorted Arrays C no 45ms O(1) Hard Binary
0005 Longest Palindromic Substring C no 9ms O(1) Medium Array
0006 ZigZag Conversion C# no O(n) Medium Array
0007 Reverse Integer C no 15ms O(1) Easy Digital
0008 String to Integer (atoi) C no 15ms O(1) Medium Digital
0009 Palindrome Number C no 185ms O(1) Easy Digital
0010 Regular Expression Matching C# no O(m*n) Hard DP
0011 Container With Most Water C O(n) 6ms O(1) Medium Greedy
0012 Integer to Roman C,C++,C# O(n) 49ms O(1) Medium Digital
0013 Roman to Integer C++ O(n) 85ms O(1) Easy Digital
0014 Longest Common Prefix C O(n*n) 3ms O(n) Easy Array
0015 3Sum C O(n*n) 97.96% O(n*n) Medium Digital
0016 3Sum Closest C O(n*n) 6ms O(1) Medium Digital
0017 Letter Combinations of a Phone Number C,C# O(n*m) 0ms O(n) Medium Queue
0018 4Sum Java O(n*n) - O(n*n) Medium Math
0020 Valid Parentheses [Java] O(n) - O(n) Easy Stack
0023 Merge k Sorted Lists C,Java O(n*logn) 9ms O(n) Hard Heap
0025 Reverse Nodes in k-Group C,Java O(n) 6ms O(1) Hard Linked
0030 Substring with Concatenation of All Words Java O(n) 23ms O(n) Hard String
0032 Longest Valid Parentheses C O(n) 6ms O(n) Hard DP
0037 Sudoku Solver C O(n) 0ms O(n*n) Hard BT
0039 Combination Sum Java O(n*n) 19ms O(n*n) Medium DFS
0040 Combination Sum II Java O(n*n) 26ms O(n*n) Medium DFS
0041 First Missing Positive C O(n) 3ms O(1) Hard Array
0042 Trapping Rain Water C O(n) 6ms O(1) Hard Array
0044 Wildcard Matching C# O(n*n) 162ms O(n*n) Hard DP
0045 Jump Game II C O(n) 6ms O(1) Hard Greey
0048 Rotate Image Java O(n*n) 2ms O(1) Medium Matrix
0050 Pow(x, n) Java O(lgn) 99.47% O(1) Medium Math
0051 N-Queens C - 3ms O(n*n) Hard Greey
0053 Maximum Subarray Java O(n) 17ms O(n) Easy DP
0054 Spiral Matrix Java O(m*n) 2ms O(m*n) Medium Matrix
0056 Merge Intervals [Java] O(n) - O(n) Medium Array
0057 Insert Interval C O(n) 6ms O(n) Hard Array
0073 Set Matrix Zeroes Java O(m*n) 1ms O(1) Medium Matrix
0074 Search a 2D Matrix Java O(n) 1ms O(1) Medium Sort
0075 Sort Colors Java O(n) 0ms O(1) Medium Array
0105 Construct Binary Tree from Preorder and Inorder Traversal Java O(n) 99.24% O(n) Medium Tree
0127 Word Ladder [Java] O(n*m*k) - O(n) Medium BFS
0136 Single Number [Java] O(n) 1MS O(1) Easy BIT
0137 Single Number II [Java] O(32n) 9MS O(1) Medium BIT
0139 Word Break [Java] O(n*n) - O(n) Medium DP
0140 Word Break II [Java] O(n*n) - O(n) Hard DP
0148 Sort List Java O(nlgn) 99.91% O(1) Medium Linked
0150 Evaluate Reverse Polish Notation [Java] O(n) - O(n) Medium Stack
0168 Excel Sheet Column Title [Java] O(lgn) 2MS O(n) Easy Math
0171 Excel Sheet Column Number [Java] O(lgn) 0MS O(n) Easy Math
0172 Factorial Trailing Zeroes [Java] O(lgn) 1MS O(1) Easy Math
0179 Largest Number Java O(n*n) 99.89% O(n) Medium Math
0189 Rotate Array [Java] O(n) - O(1) Easy Array
0190 Reverse Bits [Java] O(n) 3MS O(1) Easy BIT
0191 Number of 1 Bits [Java] O(n) 1MS O(1) Easy BIT
0201 Bitwise AND of Numbers Range [Java] O(n) 9MS O(1) Medium BIT
0202 Happy Number [Java] - 5MS O(1) Easy Math
0204 Count Primes [Java] - 22MS O(n) Easy Math
0206 Reverse Linked List Java O(n) 0MS O(1) Easy Linked
0208 Implement Trie (Prefix Tree) C O(n) 39ms O(n) Medium Tree
0215 Kth Largest Element in an Array [Java] O(n*lgn) - O(1) Medium Binary
0217 Contains Duplicate Java O(n) 99.39% O(1) Easy Array
0226 Invert Binary Tree Java O(n) 0MS O(1) Easy Tree
0231 Power of Two [Java] O(1) 2MS O(1) Easy BIT
0239 Sliding Window Maximum [Java] O(n) - O(n*k) Hard Queue
0240 Search a 2D Matrix II Java O(n + m) 13MS O(1) Medium Matrix
0300 Longest Increasing Subsequence Java O(n*lgn) 0ms O(n) Medium Binary Search DP
0301 Remove Invalid Parentheses Java - - - Hard DFS
0307 Range Sum Query - Mutable Java O(n*logn) - O(n) Medium Tree
0315 Count of Smaller Numbers After Self C O(n*logn) 16ms O(n) Hard Tree
0316 Remove Duplicate Letters C O(n) 3ms O(n) Hard Greedy Stack
0321 Create Maximum Number C O(n*k) 12ms O(n) Hard Greedy Stack
0327 Count of Range Sum C O(n*logn) 9ms O(n) Hard Devide
0329 Longest Increasing Path in a Matrix Java O(n*m) 16ms O(n*m) Hard DFS
0330 Patching Array Java O(n) 1ms O(1) Hard Greey
0335 Self Crossing Java O(n) 0ms O(1) Hard Math
0336 Palindrome Pairs Java O(n*lgm) 52ms O(n*m) Hard Tree
0338 Counting Bits Java O(n) 2ms O(n) Medium Math
0343 Integer Break Java O(n*n) 1ms O(n) Medium DP
0352 Data Stream as Disjoint Intervals Java O(n*lgn) 155ms O(n) Hard Binary Search
0354 Russian Doll Envelopes Java O(n*lgn) 13ms O(n) Hard Binary Search DP
0363 Max Sum of Rectangle No Larger Than K Java O(n^2*lgn) 99.55% O(n) Hard Devide
0370 Range Addition [Java] O(n) - O(n)
0377 Combination Sum IV Java O(n*n) 6MS O(n) Medium DP
0380 Insert Delete GetRandom O(1) Java O(1) 98.10% O(n) Medium Array
0454 4Sum II Java O(n*n) 97.52% O(n) Medium Math
0561 Array Partition I Java O(n) 90.95% O(1) Easy Array
0563 Binary Tree Tilt Java - 9MS O(n) Easy Tree
0565 Array Nesting Java O(n) 36MS O(1) Medium Array
0566 Reshape the Matrix Java O(n*m) 7MS O(n*m) Easy Martix
0567 Permutation in String Java O(n) - O(n) Medium String
0572 Subtree of Another Tree Java O(n) 13MS O(1) Easy Tree
0575 Distribute Candies Java O(n) 95.78% O(n) Easy Set
0576 Out of Boundary Paths Java - 95.73% O(n*m*N) Medium DFS
0583 Delete Operation for Two Strings Java O(n*m) 95.08% O(n*m) Medium DP
0591 Tag Validator Java O(n) 19MS O(n) Hard String
0592 Fraction Addition and Subtraction Java O(n) 16MS O(n) Medium Math
0593 Valid Square Java O(n) 20MS O(1) Medium Math
0594 Longest Harmonious Subsequence Java O(n) 71MS O(n) Easy Map
0595 Big Countries MySql - 2979MS - Easy Where
0596 Classes More Than 5 Students MySql - 2610MS - Easy Group
0597 Friend Requests I: Overall Acceptance Rate Lock - - - - -
0598 Range Addition II Java O(n) 6MS O(1) Easy Matrix
0599 Minimum Index Sum of Two Lists Java O(n) 26MS O(n) Easy Map
0600 Non-negative Integers without Consecutive Ones Java O(n) - O(n) Hard Math
0661 Image Smoother Java O(m*n) 27MS O(m*n) Easy Matrix