| # | Title | Java | Python | Golang | Difficulty | Category |
|---|---|---|---|---|---|---|
| 1 | Two Sum | Java | Python | Golang | Easy | Hash Table |
| 2 | Add Two Numbers | Java | Python | Golang | Medium | Linked List |
| 3 | Longest Substring Without Repeating Characters | Java | Python | Golang | Medium | Hash Table |
| 4 | Median of Two Sorted Arrays | Java | Python | Golang | Hard | Binary Search |
| 5 | Longest Palindromic Substring | Java | Python | Golang | Medium | DP |
| 6 | ZigZag Conversion | Java | Python | Golang | Medium | String |
| 7 | Reverse Integer | Java | Python | Golang | Easy | Math |
| 9 | Palindrome Number | Java | Python | Golang | Easy | Math |
| 10 | Regular Expression Matching | Java | Python | Golang | Hard | DP/ Backtracking |
| 11 | Container With Most Water | Java | Python | Golang | Medium | Two Pointers |
| 14 | Longest Common Prefix | Java | Python | Golang | Easy | String |
| 15 | Three Sum | Java | Python | Golang | Medium | Two Pointers |
| 16 | Three Sum Closest | Java | Python | Golang | Medium | Two Pointers |
| 17 | Letter Combinations of a Phone Number | Java | Python | Golang | Medium | Backtracking |
| 18 | Four Sum | Java | Python | Golang | Medium | Two Pointers |
| 19 | Remove Nth Node From End Of List | Java | Python | Golang | Medium | Linked List |
| 20 | Valid Parentheses | Java | Python | Golang | Easy | Stack |
| 21 | Merge Two Sorted Lists | Java | Python | Golang | Easy | Linked List |
| 22 | Generate Parentheses | Java | Python | Golang | Medium | Backtracking |
| 23 | Merge k Sorted Lists | Java | Python | Golang | Hard | Linked List/ Heap |
| 24 | Swap Pairs | Java | Python | Golang | Medium | Linked List |
| 25 | Reverse Nodes in k-Group | Java | Python | Golang | Hard | Linked List |
| 26 | Remove Duplicates from Sorted Array | Java | Python | Golang | Easy | Two Pointers |
| 27 | Remove Element | Java | Python | Golang | Easy | Two Pointers |
| 28 | Implement strStr() | Java | Python | Golang | Easy | Two Pointers |
| 29 | Divide Two Integers | Java | Python | Golang | Medium | Binary Search |
| 30 | Substring with Concatenation of All Words | Java | Python | Golang | Hard | Hash Table/ Two Pointers |
| 31 | Next Permutation | Java | Python | Golang | Medium | Array |
| 32 | Longest Valid Parentheses | Java | Python | Golang | Hard | DP |
| 33 | Search in Rotated Sorted Array | Java | Python | Golang | Medium | Binary Search |
| 34 | Find First and Last Position of Element in Sorted Array | Java | Python | Golang | Medium | Binary Search |
| 35 | Search Insert Position | Java | Python | Golang | Easy | Binary Search |
| 36 | Valid Sudoku | Java | Python | Golang | Medium | Hash Table |
| 37 | Sudoku Solver | Java | Python | Golang | Hard | Hash Table/ Backtracking |
| 38 | Count and Say | Java | Python | Golang | Easy | String |
| 39 | Combination Sum | Java | Python | Golang | Medium | Backtracking |
| 40 | Combination Sum II | Java | Python | Golang | Medium | Backtracking |
| 41 | First Missing Positive | Java | Python | Golang | Hard | Array |
| 42 | Trapping Rain Water | Java | Python | Golang | Hard | Stack/ Two Pointers |
| 44 | Wildcard Matching | Java | Python | Golang | Hard | DP/ Backtracking |
| 45 | Jump Game II | Java | Python | Golang | Hard | Greedy |
| 46 | Permutations | Java | Python | Golang | Medium | Backtracking |
| 47 | Permutations II | Java | Python | Golang | Medium | Backtracking |
| 48 | Rotate Image | Java | Python | Golang | Medium | Array |
| 49 | Group Anagrams | Java | Python | Golang | Medium | Hash Table |
| 50 | Pow(x, n) | Java | Python | Golang | Medium | Binary Search |
| 51 | N-Queens | Java | Python | Golang | Hard | Backtracking |
| 52 | N-Queens II | Java | Python | Golang | Hard | Backtracking |
| 53 | Maximum Subarray | Java | Python | Golang | Easy | DP/ Divide and Conquer |
| 54 | Spiral Matrix | Java | Python | Golang | Medium | Array |
| 55 | Jump Game | Java | Python | Golang | Medium | Greedy |
| 56 | Merge Intervals | Java | Python | Golang | Medium | Sorting |
| 57 | Insert Interval | Java | Python | Golang | Hard | Sorting |
| 58 | Length of Last Word | Java | Python | Golang | Easy | String |
| 59 | Spiral Matrix II | Java | Python | Golang | Medium | Array |
| 60 | Permutation Sequence | Java | Python | Golang | Medium | Backtracking |
| 61 | Rotate List | Java | Python | Golang | Medium | Linked List/ Two Pointers |
| 62 | Unique Paths | Java | Python | Golang | Medium | DP |
| 63 | Unique Paths II | Java | Python | Golang | Medium | DP |
| 64 | Minimal Path Sum | Java | Python | Golang | Medium | DP |
| 66 | Plus One | Java | Python | Golang | Easy | Array |
| 67 | Add Binary | Java | Python | Golang | Easy | String |
| 68 | Text Justification | Java | Python | Golang | Hard | String |
| 69 | Sqrt(x) | Java | Python | Golang | Easy | Binary Search |
| 70 | Climbing Stairs | Java | Python | Golang | Easy | DP |
| 72 | Edit Distance | Java | Python | Golang | Medium | DP |
| 73 | Set Matrix Zeroes | Java | Python | Golang | Medium | Array |
| 74 | Search Target | Java | Python | Golang | Medium | Binary Search |
| 75 | Sort Colors | Java | Python | Golang | Medium | Two Pointers |
| 76 | Minimum Window Substring | Java | Python | Golang | Hard | Two Pointer/ Hash Table |
| 77 | Combinations | Java | Python | Golang | Medium | Backtracking |
| 78 | Subsets | Java | Python | Golang | Medium | Backtracking |
| 79 | Word Search | Java | Python | Golang | Medium | Backtracking |
| 80 | Remove Duplicates from Sorted Arrays | Java | Python | Golang | Medium | Two Pointers |
| 81 | Search in Rotated Sorted Array II | Java | Python | Golang | Medium | Binary Search |
| 82 | Remove Duplicates from Sorted List II | Java | Python | Golang | Medium | Linked List |
| 83 | Remove Duplicates from Sorted List | Java | Python | Golang | Easy | Linked List |
| 84 | Largest Rectangle Area | Java | Python | Golang | Hard | Stack |
| 85 | Maximum Rectangle | Java | Python | Golang | Hard | DP |
| 86 | Partition List | Java | Python | Golang | Medium | Linked List |
| 87 | Scramble String | Java | Python | Golang | Hard | DP |
| 88 | Merge Sorted Array | Java | Python | Golang | Easy | Array |
| 89 | Gray Code | Java | Python | Golang | Medium | Backtracking |
| 90 | Subset II | Java | Python | Golang | Medium | Backtracking |
| 91 | Decode Ways | Java | Python | Golang | Medium | DP |
| 92 | Reverse Linked List II | Java | Python | Golang | Medium | Linked List |
| 93 | Restore IP Address | Java | Python | Golang | Medium | Backtracking |
| 94 | Binary Tree Inorder Traversal | Java | Python | Golang | Medium | Tree/ Stack |
| 95 | Unique Binary Search Tree II | Java | Python | Golang | Medium | Tree/ DP |
| 96 | Unique Binary Search Tree | Java | Python | Golang | Medium | Tree/ DP |
| 97 | Interleaving String | Java | Python | Golang | Hard | DP |
| 98 | Valid Binary Search Tree | Java | Python | Golang | Medium | Tree/ DFS |
| 99 | Recover Binary Search Tree | Java | Python | Golang | Hard | Tree/ DFS |
| 100 | Same Tree | Java | Python | Golang | Easy | Tree/ DFS |
| 101 | Symmetric Tree | Java | Python | Golang | Easy | Tree/ DFS |
| 102 | Binary Tree Level Order Traversal | Java | Python | Golang | Medium | Tree/ BFS |
| 103 | Binary Tree Zigzag Level Order Traversal | Java | Python | Golang | Medium | Tree/ BFS |
| 104 | Maximum Depth of Binary Tree | Java | Python | Golang | Easy | Tree/ DFS |
| 105 | ConStruct Binary Tree from Preorder and Inorder Traversal | Java | Python | Golang | Medium | Tree/ DFS |
| 106 | Construct Binary Tree From Inorder and Postorder Traversal | Java | Python | Golang | Medium | Tree/ DFS |
| 107 | Binary Tree Level Order Traversal II | Java | Python | Golang | Easy | Tree/ BFS |
| 108 | Convert Sorted Array to Binary Search Tree | Java | Python | Golang | Easy | Tree/ DFS |
| 109 | Convert Sorted List to Binary Search Tree | Java | Python | Golang | Medium | DFS/ Linked List |
| 110 | Balanced Binary Tree | Java | Python | Golang | Easy | Tree/ DFS |
| 111 | Minimum Depth of Binary Tree | Java | Python | Golang | Easy | Tree/ DFS |
| 112 | Path Sum | Java | Python | Golang | Easy | Tree/ DFS |
| 113 | Path Sum II | Java | Python | Golang | Medium | Tree/ DFS |
| 114 | Flatten Binary Tree to Linked List | Java | Python | Golang | Medium | Tree/ DFS |
| 115 | Distinct Subsequences | Java | Python | Golang | Hard | DP |
| 116 | Populating Next Right Pointers for Each Node | Java | Python | Golang | Medium | Tree/ DFS |
| 117 | Populating Next Right Pointers for Each Node II | Java | Python | Golang | Medium | Tree/ DFS |
| 118 | Pascal's Triangle | Java | Python | Golang | Easy | Array |
| 119 | Pascal's Triangle II | Java | Python | Golang | Easy | Array/ DP |
| 120 | Triangle | Java | Python | Golang | Medium | DP |
| 121 | Best Time to Buy and Sell Stock | Java | Python | Golang | Easy | Array |
| 122 | Best Time to Buy and Sell Stock II | Java | Python | Golang | Easy | Array |
| 123 | Best Time to Buy and Sell Stock III | Java | Python | Golang | Hard | Array |
| 124 | Binary Tree Maximum Path Sum | Java | Python | Golang | Hard | Tree/ DFS |
| 125 | Valid Palindrome | Java | Python | Golang | Easy | Two Pointers |
| 126 | Word Ladder II | Java | Python | Golang | Hard | BFS |
| 127 | Word Ladder | Java | Python | Golang | Medium | BFS |
| 128 | Longest Consecutive Sequence | Java | Python | Golang | Hard | Union Find |
| 129 | Sum Root to Leaf Numbers | Java | Python | Golang | Medium | Tree/ DFS |
| 130 | Surrounded Regions | Java | Python | Golang | Medium | DFS/ BFS/ Union Find |
| 131 | Palindrome Partitioning | Java | Python | Golang | Medium | Backtracking |
| 132 | Palindrome Partitioning II | Java | Python | Golang | Hard | DP |
| 133 | Clone Graph | Java | Python | Meduim | DFS/ BFS | |
| 134 | Gas Station | Java | Python | Golang | Medium | Greedy |
| 135 | Candy | Java | Python | Golang | Hard | Greedy |
| 136 | Single Number | Java | Python | Golang | Easy | Bit Manipulation |
| 137 | Single Number II | Java | Python | Golang | Medium | Bit Manipulation |
| 138 | Copy List with Random Pointer | Java | Python | Golang | Medium | Hash Table |
| 139 | Word Break | Java | Python | Golang | Medium | DP |
| 140 | Word Break II | Java | Python | Golang | Hard | DP/ Backtracking |
| 141 | Linked List Cycle | Java | Python | Golang | Easy | Linked List |
| 142 | Linked List Cycle II | Java | Python | Golang | Medium | Linked List |
| 143 | Reorder List | Java | Python | Golang | Medium | Linked List |
| 144 | Binary Tree Preorder Traversal | Java | Python | Golang | Medium | Tree/ DFS |
| 145 | Binary Tree Postorder Traversal | Java | Python | Golang | Hard | Tree/ DFS |
| 146 | LRU Cache | Java | Python | Golang | Hard | Hash Table |
| 147 | Insertion Sort List | Java | Python | Golang | Medium | Linked List/ Sorting |
| 148 | Sort List | Java | Python | Golang | Medium | Linked List/ Sorting |
| 149 | Max Points on a Line | Java | Python | Golang | Hard | Hash Table |
| 150 | Evaluate Reverse Polish Notation | Java | Python | Golang | Medium | Stack |
| 151 | Reverse Words in a String | Java | Python | Golang | Medium | String |
| 152 | Maximum Product Subarray | Java | Python | Golang | Medium | DP |
| 153 | Find Minimum in Rotated Sorted Array | Java | Python | Golang | Medium | Binary Search |
| 154 | Find Minimum in Rotated Sorted Array II | Java | Python | Golang | Hard | Binary Search |
| 155 | Min Stack | Java | Python | Golang | Easy | Stack |
| 156 | Binary Tree Upside Down* | Java | Python | Golang | Medium | Tree/ DFS |
| 159 | Longest Substring with At Most Two Distinct Characters* | Java | Python | Golang | Medium | Hash Table/ Array |
| 160 | Intersection of Two Linked List | Java | Python | Golang | Easy | Linked List |
| 161 | One Edit Distance* | Java | Python | Golang | Easy | String |
| 162 | Find Peak Element | Java | Python | Golang | Medium | Binary Search |
| 163 | Missing Ranges* | Java | Python | Golang | Medium | Array |
| 164 | Maximum Gap | Java | Python | Golang | Hard | Sorting |
| 165 | Compare Version Numbers | Java | Python | Golang | Medium | String |
| 166 | Fraction to Recurring Decimal | Java | Python | Golang | Medium | Hash Table |
| 167 | Two Sum II - Input array is sorted | Java | Python | Golang | Easy | Binary Search |
| 168 | Excel Sheet Column Title | Java | Python | Golang | Easy | Math |
| 169 | Majority Element | Java | Python | Golang | Easy | Array |
| 170 | Two Sum III - Data structure design* | Java | Python | Golang | Medium | Binary Search |
| 171 | Excel Sheet Column Number | Java | Python | Golang | Easy | Math |
| 172 | Factorial Trailing Zeroes | Java | Python | Golang | Easy | Math |
| 173 | Binary Search Tree Iterator | Java | Python | Golang | Medium | Tree/ Stack |
| 174 | Dungeon Game | Java | Python | Golang | Hard | DP |
| 179 | Largest Number | Java | Python | Golang | Medium | Sorting |
| 186 | Reverse Words in a String II* | Java | Python | Golang | Easy | String |
| 187 | Repeated DNA Sequences | Java | Python | Golang | Medium | Hash Table |
| 188 | Best Time to Buy and Sell Stock IV | Java | Python | Golang | Hard | DP |
| 189 | Rotate Array | Java | Python | Golang | Easy | Array |
| 190 | Reverse Bits | Java | Python | Golang | Easy | Bit Manipulation |
| 191 | Number of 1 Bits | Java | Python | Golang | Easy | Bit Manipulation |
| 198 | House Robber | Java | Python | Golang | Easy | DP |
| 199 | Binary Tree Right Side View | Java | Python | Golang | Medium | Tree/ DFS |
| 200 | Number of Islands | Java | Python | Golang | Medium | DFS/ BFS/ Union Find |
| 201 | Range Bit Wise And | Java | Python | Golang | Medium | Bit Manipulation |
| 202 | Happy Number | Java | Python | Golang | Easy | Hash Table |
| 203 | Remove Linked List Elements | Java | Python | Golang | Easy | Linked List |
| 204 | Count Primes | Java | Python | Golang | Easy | Hash Table |
| 205 | Isomorphic Strings | Java | Python | Golang | Easy | Hash Table |
| 206 | Reverse List | Java | Python | Golang | Easy | Linked List |
| 207 | Course Schedule | Java | Python | Golang | Medium | DFS/ BFS/ Graph |
| 208 | Implement Trie(Prefix Tree) | Java | Python | Golang | Medium | Trie |
| 209 | Minimum Size Subarray Sum | Java | Python | Golang | Medium | Two Pointers |
| 210 | Course Schedule II | Java | Python | Golang | Medium | DFS/ BFS/ Graph |
| 211 | Add and Search Word - Data Structure Design | Java | Python | Golang | Medium | Trie |
| 212 | Word Search II | Java | Python | Golang | Hard | Trie/ Backtracking |
| 213 | House Robber II | Java | Python | Golang | Medium | DP |
| 214 | Shortest Palindrome | Java | Python | Golang | Hard | KMP |
| 215 | Kth Largest Element in an Array | Java | Python | Golang | Medium | Heap |
| 216 | Combination Sum III | Java | Python | Golang | Medium | Backtracking |
| 217 | Contains Duplicates | Java | Python | Golang | Easy | Hash Table |
| 218 | The Skyline Problem | Java | Python | Golang | Hard | Heap/ Binary Indexed Tree/ Segment Tree |
| 219 | Contains Duplicates II | Java | Python | Golang | Easy | Hash Table |
| 220 | Contains Duplicates III | Java | Python | Golang | Medium | Binary Search Tree |
| 221 | Maximum Square | Java | Python | Golang | Medium | DP |
| 222 | Count Complete Tree Nodes | Java | Python | Golang | Medium | Binary Search |
| 223 | Rectangle Area | Java | Python | Golang | Medium | Math |
| 225 | Implement Stack Using Queue | Java | Python | Golang | Easy | Stack |
| 226 | Invert Binary Tree | Java | Python | Golang | Easy | Tree |
| 228 | Summary Ranges | Java | Python | Golang | Medium | Array |
| 229 | Majority Element II | Java | Python | Golang | Medium | Array |
| 230 | Kth Smallest Element in a BST | Java | Python | Golang | Medium | Tree/ Binary Search |
| 231 | Power of Two | Java | Python | Golang | Easy | Bit Manipulation |
| 232 | Implement Queue Using Stack | Java | Python | Golang | Easy | Stack |
| 233 | Number of Digit One | Java | Python | Golang | Hard | Math |
| 234 | Palindrome Linked List | Java | Python | Golang | Easy | Linked List |
| 235 | Lowest Common Ancestor BST | Java | Python | Golang | Easy | Tree |
| 236 | Lowest Common Ancestor BT | Java | Python | Golang | Medium | Tree |
| 237 | Delete Node in a Linked List | Java | Python | Golang | Easy | Linked List |
| 238 | Product of Array Except Self | Java | Python | Golang | Medium | Array |
| 239 | Sliding Window Maximum | Java | Python | Golang | Hard | Heap |
| 240 | Search a 2D Matrix II | Java | Python | Golang | Medium | Binary Search |
| 241 | Different Ways to Add Parentheses | Java | Python | Golang | Medium | Divide and Conquer |
| 242 | Valid Anagram | Java | Python | Golang | Easy | Hash Table |
| 243 | Shortest Word Distance* | Java | Python | Golang | Easy | Array |
| 244 | Shortest Word Distance II* | Java | Python | Golang | Medium | Array |
| 245 | Shortest Word Distance III* | Java | Python | Golang | Medium | Array |
| 246 | Strobogrammatic Number* | Java | Python | Golang | Easy | Hash Table |
| 247 | Strobogrammatic Number II* | Java | Python | Golang | Easy | Hash Table |
| 248 | Strobogrammatic Number III* | Java | Python | Golang | Medium | Hash Table |
| 249 | Group Shifted Strings* | Java | Python | Golang | Medium | Hash Table |
| 250 | Count Univalue Subtrees* | Java | Python | Golang | Medium | Tree/ DFS |
| 251 | Flatten 2D Vector* | Java | Python | Golang | Easy | Array |
| 252 | Meeting Rooms* | Java | Python | Golang | Easy | Sorting |
| 253 | Meeting Rooms II* | Java | Python | Golang | Medium | Heap |
| 254 | Factor Combinations* | Java | Python | Golang | Medium | DFS |
| 255 | Verify Preorder Sequence in Binary Search Tree* | Java | Python | Golang | Hard | Tree/ DFS |
| 256 | Paint House* | Java | Python | Golang | Medium | DP |
| 257 | Binary Tree Paths | Java | Python | Golang | Easy | Tree/ DFS |
| 258 | Add Digits | Java | Python | Golang | Easy | Math |
| 259 | 3Sum Smaller* | Java | Python | Golang | Medium | Array/ Two Pointers |
| 260 | Single Number III | Java | Python | Golang | Medium | Bit Manipulation |
| 261 | Graph Valid Tree* | Java | Python | Golang | Medium | Union Find |
| 263 | Ugly Number | Java | Python | Golang | Easy | Math |
| 264 | Ugly Number II | Java | Python | Golang | Medium | Math |
| 265 | Paint House II* | Java | Python | Golang | Hard | DP |
| 266 | Palindrome Permutation* | Java | Python | Golang | Easy | Hash Table |
| 267 | Palindrome Permutation II | Java | Python | Golang | Medium | Hash Table/ Backtracking |
| 268 | Missing Number | Java | Python | Golang | Easy | Bit Manipulation |
| 269 | Alien Dictionary* | Java | Python | Golang | Hard | Graph/ DFS |
| 270 | Closest Binary Search Tree Value* | Java | Python | Golang | Easy | Tree/ DFS |
| 271 | Encode and Decode Strings* | Java | Python | Golang | Medium | String |
| 272 | Closest Binary Search Tree Value II* | Java | Python | Golang | Hard | Tree/ DFS |
| 273 | Integer to English Words | Java | Python | Golang | Hard | String |
| 274 | H-Index | Java | Python | Golang | Medium | Sorting |
| 275 | H-Index II | Java | Python | Golang | Medium | Binary Search |
| 276 | Paint Fence* | Java | Python | Golang | Easy | DP |
| 277 | Find the Celebrity* | Java | Python | Golang | Medium | Array |
| 278 | First Bad Version | Java | Python | Golang | Easy | Binary Search |
| 279 | Perfect Squares | Java | Python | Golang | Medium | BFS/ DP |
| 280 | Wiggle Sort* | Java | Python | Golang | Medium | Array |
| 281 | Zigzag Iterator* | Java | Python | Golang | Medium | Array |
| 282 | Expression Add Operators | Java | Python | Golang | Hard | DFS |
| 283 | Move Zeroes | Java | Python | Golang | Easy | Array/ Two Pointers |
| 284 | Peeking Iterator | Java | Python | Golang | Medium | Design |
| 285 | Inorder Successor in BST* | Java | Python | Golang | Medium | Tree/ DFS |
| 286 | Walls and Gates* | Java | Python | Golang | Medium | DFS |
| 287 | Find the Duplicate Number | Java | Python | Golang | Medium | Binary Search/ Two Pointers |
| 288 | Unique Word Abbreviation* | Java | Python | Golang | Easy | Hash Table |
| 289 | Game Of Life | Java | Python | Golang | Medium | Array |
| 290 | Word Pattern | Java | Python | Golang | Easy | Hash Table |
| 291 | Word Pattern II* | Java | Python | Golang | Hard | Hash Table/ Backtracking |
| 292 | Nim Game | Java | Python | Golang | Easy | Brainteaser |
| 293 | Flip Game* | Java | Python | Golang | Easy | String |
| 294 | Flip Game II* | Java | Python | Golang | Medium | Backtracking |
| 295 | Find Median from Data Stream | Java | Python | Golang | Hard | Heap |
| 296 | Best Meeting Point* | Java | Python | Golang | Medium | Array |
| 297 | Serialize and Deserialize Binary Tree | Java | Python | Golang | Hard | Tree |
| 298 | Binary Tree Longest Consecutive Sequence* | Java | Python | Golang | Medium | Tree/ DFS |
| 299 | Bulls and Cows | Java | Python | Golang | Medium | Hash Table |
| 300 | Longest Increasing Subsequence | Java | Python | Golang | Medium | DP/ Binary Search |
| 301 | Remove Invalid Parentheses | Java | Python | Golang | Hard | DFS |
| 302 | Smallest Rectangle Enclosing Black Pixels* | Java | Python | Golang | Hard | DFS |
| 303 | Range Sum Query - Immutable | Java | Python | Golang | Easy | DP |
| 304 | Range Sum Query 2D - Immutable | Java | Python | Golang | Medium | DP |
| 305 | Number of Islands II* | Java | Python | Golang | Hard | Union Find |
| 306 | Additive Number | Java | Python | Golang | Medium | Backtracking |
| 307 | Range Sum Query - Mutable | Java | Python | Golang | Medium | Binary Indexed Tree/ Segment Tree |
| 308 | Range Sum Query 2D - Mutable* | Java | Python | Golang | Medium | Binary Indexed Tree/ Segment Tree |
| 309 | Best Time to Buy and Sell Stock with Cooldown | Java | Python | Golang | Medium | DP |
| 310 | Minimum Height Trees | Java | Python | Golang | Medium | BFS/ Graph |
| 311 | Sparse Matrix Multiplication* | Java | Python | Golang | Medium | Array |
| 312 | Burst Balloons | Java | Python | Golang | Hard | DP |
| 313 | Super Ugly Number | Java | Python | Golang | Medium | Heap/ DP |
| 314 | Binary Tree Vertical Order Traversal* | Java | Python | Golang | Medium | BFS |
| 315 | Count of Smaller Numbers After Self | Java | Python | Golang | Hard | Binary Search |
| 316 | Remove Duplicate Letters | Java | Python | Golang | Hard | Hash Table |
| 317 | Shortest Distance from All Buildings* | Java | Python | Golang | Hard | BFS |
| 318 | Maximum Product of Word Lengths | Java | Python | Golang | Medium | Bit Manipulation |
| 319 | Bulb Switcher | Java | Python | Golang | Medium | Brainteaser |
| 320 | Generalized Abbreviation* | Java | Python | Golang | Medium | Bit Manipulation |
| # | Title | MySQL | Difficulty |
|---|---|---|---|
| 175 | Combine Two Tables | MySQL | Golang |
| 176 | Second Highest Salary | MySQL | Golang |
| 177 | Nth Highest Salary | MySQL | Golang |
| 178 | Rank Scores | MySQL | Golang |
| 180 | Consecutive Numbers | MySQL | Golang |
| 181 | Employees Earning More Than Their Managers | MySQL | Golang |
| 182 | Duplicate Emails | MySQL | Golang |
| 183 | Customers Who Never Order | MySQL | Golang |
| 184 | Department Highest Salary | MySQL | Golang |
| 185 | Department Top Three Salary | MySQL | Golang |
