Solutions to LeetCode Problems # Title 1 Two Sum 2 Add Two Numbers 3 Longest Substring Without Repeating Characters 7 Reverse Integer 9 Palindrome Number 12 Integer to Roman 13 Roman to Integer 14 Longest Common Prefix 20 Valid Parentheses 21 Merge Two Sorted Lists 24 Swap Nodes in Pairs 26 Remove Duplicates from Sorted Array 27 Remove Element 28 Implement strStr() 33 Search in Rotated Sorted Array 35 Search Insert Position 38 Count and Say 41 First Missing Positive 49 Group Anagrams 53 Maximum Subarray 54 Spiral Matrix 55 Jump Game 56 Merge Intervals 58 Length of Last Word 64 Minimum Path Sum 66 Plus One 67 Add Binary 69 Sqrt(x) 70 Climbing Stairs 83 Remove Duplicates from Sorted List 88 Merge Sorted Array 94 Binary Tree Inorder Traversal 100 Same Tree 101 Symmetric Tree 102 Binary Tree Level Order Traversal 104 Maximum Depth of Binary Tree 105 Construct Binary Tree from Preorder and Inorder Traversal 106 Construct Binary Tree from Inorder and Postorder Traversal 107 Binary Tree Level Order Traversal II 108 Convert Sorted Array to Binary Search Tree 110 Balanced Binary Tree 111 Minimum Depth of Binary Tree 112 Path Sum 116 Populating Next Right Pointers in Each Node 118 Pascal's Triangle 119 Pascal's Triangle II 121 Best Time to Buy and Sell Stock 122 Best Time to Buy and Sell Stock II 124 Binary Tree Maximum Path Sum 125 Valid Palindrome 127 Word Ladder 136 Single Number 139 Word Break 141 Linked List Cycle 144 Binary Tree Preorder Traversal 145 Binary Tree Postorder Traversal 146 LRU Cache 155 Min Stack 153 Find Minimum in Rotated Sorted Array 160 Intersection of Two Linked Lists 167 Two Sum II - Input array is sorted 168 Excel Sheet Column Title 169 Majority Element 171 Excel Sheet Column Number 172 Factorial Trailing Zeroes 189 Rotate Array 190 Reverse Bits 191 Number of 1 Bits 198 House Robber 200 Number of Islands 201 Bitwise AND of Numbers Range 202 Happy Number 203 Remove Linked List Elements 204 Count Primes 205 Isomorphic Strings 206 Reverse Linked List 208 Implement Trie (Prefix Tree) 217 Contains Duplicate 219 Contains Duplicate II 221 Maximal Square 225 Implement Stack using Queues 226 Invert Binary Tree 230 Kth Smallest Element in a BST 231 Power of Two 232 Implement Queue using Stacks 234 Palindrome Linked List 235 Lowest Common Ancestor of a Binary Search Tree 237 Delete Node in a Linked List 238 Product of Array Except Self 242 Valid Anagram 257 Binary Tree Paths 258 Add Digits 263 Ugly Number 268 Missing Number 278 First Bad Version 283 Move Zeroes 290 Word Pattern 292 Nim Game 299 Bulls and Cows 303 Range Sum Query - Immutable 309 Best Time to Buy and Sell Stock with Cooldown 322 Coin Change 326 Power of Three 328 Odd Even Linked List 342 Power of Four 344 Reverse String 345 Reverse Vowels of a String 349 Intersection of Two Arrays 350 Intersection of Two Arrays II 367 Valid Perfect Square 383 Ransom Note 387 First Unique Character in a String 389 Find the Difference 394 Decode String 402 Remove K Digits 403 Frog Jump 405 Convert a Number to Hexadecimal 404 Sum of Left Leaves 412 Fizz Buzz 416 Partition Equal Subset Sum 438 Find All Anagrams in a String 451 Sort Characters By Frequency 476 Number Complement 485 Max Consecutive Ones 498 Diagonal Traverse 509 Fibonacci Number 520 Detect Capital 525 Contiguous Array 540 Single Element in a Sorted Array 543 Diameter of Binary Tree 560 Subarray Sum Equals K 567 Permutation in String 575 Distribute Candies 623 Add One Row to Tree 645 Set Mismatch 678 Valid Parenthesis String 700 Search in a Binary Search Tree 706 Design HashMap 709 To Lower Case 724 Find Pivot Index 733 Flood Fill 747 Largest Number At Least Twice of Others 771 Jewels and Stones 836 Rectangle Overlap 844 Backspace String Compare 876 Middle of the Linked List 883 Projection Area of 3D Shapes 884 Uncommon Words from Two Sentences 901 Online Stock Span 905 Sort Array By Parity 912 Sort an Array 918 Maximum Sum Circular Subarray 935 Knight Dialer 977 Squares of a Sorted Array 984 String Without AAA or BBB 993 Cousins in Binary Tree 997 Find the Town Judge 1008 Construct Binary Search Tree from Preorder Traversal 1009 Complement of Base 10 Integer 1046 Last Stone Weight 1143 Longest Common Subsequence 1232 Check If It Is a Straight Line 1277 Count Square Submatrices with All Ones 1332 Remove Palindromic Subsequences 1394 Find Lucky Integer in an Array 1426 Counting Elements 1427 Perform String Shifts 1428 Leftmost Column with at Least a One 1429 First Unique Number 1430 Check If a String Is a Valid Sequence from Root to Leaves Path in a Binary Tree 1461 Check If a String Contains All Binary Codes of Size K 1572 Matrix Diagonal Sum Problems solved: 172