LeetCode
I classify 200 leetcode problems into fundamental algorithms and upload my C++ and Python solution to who concern. Moreover, you can visit my profie in LeetCode, I will upload solutions for some problems regularly. Hope you have great time practicing Leetcode.
WEEK 1
| # | Title | Difficulty |
|---|---|---|
| Array | ||
| 15 | 3Sum | Medium |
| 1324 | Print Words Vertically | Medium |
| 566 | Reshape the Matrix | Easy |
| 14 | Longest Common Prefix | Easy |
| 763 | Partition Labels | Medium |
| 55 | Jump Game | Medium |
| 33 | Search in Rotated Sorted Array | Medium |
| 1465 | Maximum Area of a Piece of Cake After Horizontal and Vertical Cuts | Medium |
| 1894 | Find the Student that Will Replace the Chalk | Medium |
| 62 | Unique Paths | Medium |
| 714 | Best Time to Buy and Sell Stock with Transaction Fee | Medium |
| 36 | Valid Sudoku | Medium |
| 929 | Unique Email Addresses | Easy |
WEEK 2
| # | Title | Difficulty |
|---|---|---|
| Two Pointers | ||
| 350 | Intersection of Two Arrays II | Easy |
| 560 | Subarray Sum Equals K | Medium |
| 1234 | Replace the Substring for Balanced String | Medium |
| 632 | Smallest Range Covering Elements from K Lists | Hard |
| 3 | Longest Substring Without Repeating Characters | Medium |
| 11 | Container With Most Water | Medium |
| 283 | Move Zeroes | Easy |
| 845 | Longest Mountain in Array | Medium |
| 209 | Minimum Size Subarray Sum | Medium |
| 287 | Find the Duplicate Number | Medium |
| 16 | 3Sum Closest | Medium |
WEEK 3
| # | Title | Difficulty |
|---|---|---|
| STACK AND QUEUE | ||
| 1249 | Minimum Remove to Make Valid Parentheses | Medium |
| 856 | Score of Parentheses | Medium |
| 946 | Validate Stack Sequences | Medium |
| 609 | Find Duplicate File in System | Medium |
| 503 | Next Greater Element II | Medium |
| 1047 | Remove All Adjacent Duplicates In String | Easy |
WEEK 4
| # | Title | Difficulty |
|---|---|---|
| GREEDY | ||
| 122 | Best Time to Buy and Sell Stock II | Easy |
| 392 | Is Subsequence | Easy |
| 1029 | Two City Scheduling | Easy |
| 406 | Queue Reconstruction by Height | Medium |
| 921 | Minimum Add to Make Parentheses Valid | Medium |
| 1338 | Reduce Array Size to The Half | Medium |
| 1433 | Check If a String Can Break Another String | Medium |
| 1833 | Maximum Ice Cream Bars | Medium |
| 1753 | Maximum Score From Removing Stones | Medium |
| 1191 | K-Concatenation Maximum Sum | Medium |
| 1899 | Merge Triplets to Form Target Triplet | Medium |
WEEK 5
| # | Title | Difficulty |
|---|---|---|
| HEAP | ||
| 378 | Kth Smallest Element in a Sorted Matrix | Medium |
| 659 | Split Array into Consecutive Subsequences | Medium |
| 692 | Top K Frequent Words | Medium |
| 973 | K Closest Points to Origin | Medium |
| 1054 | Distant Barcodes | Medium |
| 218 | The Skyline Problem | Hard |
| 857 | Minimum Cost to Hire K Workers | Hard |
WEEK 6
| # | Title | Difficulty |
|---|---|---|
| LINKED LIST | ||
| 21 | Merge Two Sorted Lists | Easy |
| 234 | Palindrome Linked List | Easy |
| 24 | Swap Nodes in Pairs | Medium |
| 86 | Partition List | Medium |
| 92 | Reverse Linked List II | Medium |
| 148 | Sort List | Medium |
| 430 | Flatten a Multilevel Doubly Linked List | Medium |
| 445 | Add Two Numbers II | Medium |
| 725 | Split Linked List in Parts | Medium |
| 1019 | Next Greater Node In Linked List | Medium |
WEEK 7
| # | Title | Difficulty |
|---|---|---|
| GRAPH | ||
| 1387 | Sort Integers by The Power Value | Medium |
| 997 | Find the Town Judge | Easy |
| 797 | All Paths From Source to Target | Medium |
| 1042 | Flower Planting With No Adjacent | Medium |
| 787 | Cheapest Flights Within K Stops | Medium |
WEEK 8
| # | Title | Difficulty |
|---|---|---|
| BFS | ||
| 417 | Pacific Atlantic Water Flow | Medium |
| 529 | Minesweeper | Medium |
| 752 | Open the Lock | Medium |
| 909 | Snakes and Ladders | Medium |
| 1129 | Shortest Path with Alternating Colors | Medium |
| 1162 | As Far from Land as Possible | Medium |
| 1391 | Check if There is a Valid Path in a Grid | Medium |
| 490 | The Maze | Medium |
| 505 | The Maze II | Medium |
| 499 | The Maze III | Medium |
WEEK 9
| # | Title | Difficulty |
|---|---|---|
| DFS | ||
| 695 | Max Area of Island | Medium |
| 1254 | Number of Closed Islands | Medium |
| 130 | Surrounded Regions | Medium |
| 934 | Shortest Bridge | Medium |
| 841 | Keys and Rooms | Medium |
| 1306 | Jump Game III | Medium |
| 399 | Evaluate Division | Medium |
| 785 | Is Graph Bipartite? | Medium |
| 133 | Clone Graph | Medium |
| 207 | Course Schedule | Medium |
| 210 | Course Schedule II | Medium |
| 802 | Find Eventual Safe States | Medium |
| 1462 | Course Schedule IV | Medium |
WEEK 10
| # | Title | Difficulty |
|---|---|---|
| DJISKTRA | ||
| 1135 | Connecting Cities With Minimum Cost | Medium |
| 743 | Network Delay Time | Medium |
| 1976 | Number of Ways to Arrive at Destination | Medium |
| 882 | Reachable Nodes In Subdivided Graph | Hard |
WEEK 11
| # | Title | Difficulty |
|---|---|---|
| UNION FIND | ||
| 323 | Number of Connected Components in an Undirected Graph | Medium |
| 1319 | Number of Operations to Make Network Connected | Medium |
| 128 | Longest Consecutive Sequence | Hard |
| 765 | Couples Holding Hands | Hard |
| 778 | Swim in Rising Water | Hard |
| 1168 | Optimize Water Distribution in a Village | Hard |
| 209 | Minimum Size Subarray Sum | Medium |
| 547 | Number of Provinces | Medium |
| 684 | Redundant Connection | Medium |
WEEK 12
| # | Title | Difficulty |
|---|---|---|
| TREE | ||
| 700 | Search in a Binary Search Tree | Easy |
| 559 | Maximum Depth of N-ary Tree | Easy |
| 1022 | Sum of Root To Leaf Binary Numbers | Easy |
| 872 | Leaf-Similar Trees | Easy |
| 637 | Average of Levels in Binary Tree | Easy |
| 100 | Same Tree | Easy |
| 94 | Binary Tree Inorder Traversal | Medium |
| 513 | Find Bottom Left Tree Value | Medium |
| 515 | Find Largest Value in Each Tree Row | Medium |
| 144 | Binary Tree Preorder Traversal | Medium |
| 102 | Binary Tree Level Order Traversal | Medium |
| 199 | Binary Tree Right Side View | Medium |
| 366 | Find Leaves of Binary Tree | Medium |
| 814 | Binary Tree Pruning | Medium |
| 1325 | Delete Leaves With a Given Value | Medium |
| 606 | Construct String from Binary Tree | Easy |
| 543 | Diameter of Binary Tree | Easy |
| 863 | All Nodes Distance K in Binary Tree | Medium |
| 1245 | Tree Diameter | Medium |
WEEK 13
| # | Title | Difficulty |
|---|---|---|
| BINARY SEARCH TREE | ||
| 653 | Two Sum IV - Input is a BST | Easy |
| 230 | Kth Smallest Element in a BST | Medium |
| 449 | Serialize and Deserialize BST | Medium |
| 538 | Convert BST to Greater Tree | Easy |
| 1038 | Binary Search Tree to Greater Sum Tree | Medium |
| 1382 | Balance a Binary Search Tree | Medium |
| 701 | Insert into a Binary Search Tree | Medium |
| 1305 | All Elements in Two Binary Search Trees | Medium |
WEEK 14
| # | Title | Difficulty |
|---|---|---|
| BINARY TREE | ||
| 1351 | Count Negative Numbers in a Sorted Matrix | Easy |
| 875 | Koko Eating Bananas | Medium |
| 287 | Find the Duplicate Number | Medium |
| 153 | Find Minimum in Rotated Sorted Array | Medium |
| 33 | Search in Rotated Sorted Array | Medium |
| 50 | Pow(x, n) | Medium |
| 1201 | Ugly Number III | Medium |
| 29 | Divide Two Integers | Medium |
| 35 | Search Insert Position | Easy |
| 129 | Sum Root to Leaf Numbers | Medium |
| 1339 | Maximum Product of Splitted Binary Tree | Medium |
| 331 | Verify Preorder Serialization of a Binary Tree | Medium |
WEEK 15
| # | Title | Difficulty |
|---|---|---|
| MATH | ||
| 7 | Reverse Integer | Easy |
| 2 | Add Two Numbers | Medium |
| 553 | Optimal Division | Medium |
| 1362 | Closest Divisors | Medium |
| 1006 | Clumsy Factorial | Medium |
| 592 | Fraction Addition and Subtraction | Medium |
| 640 | Solve the Equation | Medium |
| 279 | Perfect Squares | Medium |
| 12 | Integer to Roman | Medium |
| 866 | Prime Palindrome | Medium |
| 223 | Rectangle Area | Medium |
| 1227 | Airplane Seat Assignment Probability | Medium |
| 1230 | Toss Strange Coins | Medium |
| 1093 | Statistics from a Large Sample | Medium |
| 1017 | Convert to Base -2 | Medium |
WEEK 16
| # | Title | Difficulty |
|---|---|---|
| Dynamic Programming | ||
| 413 | Arithmetic Slices | Medium |
| 712 | Minimum ASCII Delete Sum for Two Strings | Medium |
| 1143 | Longest Common Subsequence | Medium |
| 64 | Minimum Path Sum | Medium |
| 343 | Integer Break | Medium |
| 718 | Maximum Length of Repeated Subarray | Medium |
| 1664 | Ways to Make a Fair Array | Medium |
| 983 | Minimum Cost For Tickets | Medium |
| 1043 | Partition Array for Maximum Sum | Medium |
| 1641 | Count Sorted Vowel Strings | Medium |
| 907 | Sum of Subarray Minimums | Medium |
| 322 | Coin Change | Medium |
| 790 | Domino and Tromino Tiling | Medium |
| 1235 | Maximum Profit in Job Scheduling | Hard |
| 1411 | Number of Ways to Paint N × 3 Grid | Hard |
| 115 | Distinct Subsequences | Hard |
WEEK 17
| # | Title | Difficulty |
|---|---|---|
| BACKTRACKING | ||
| 1641 | Count Sorted Vowel Strings | Medium |
| 1079 | Letter Tile Possibilities | Medium |
| 77 | Combinations | Medium |
| 39 | Combination Sum | Medium |
| 216 | Combination Sum III | Medium |
| 1780 | Check if Number is a Sum of Powers of Three | Medium |
| 22 | Generate Parentheses | Medium |
| 46 | Permutations | Medium |
| 784 | Letter Case Permutation | Medium |
| 1415 | The k-th Lexicographical String of All Happy Strings of Length n | Medium |
| 37 | Sudoku Solver | Hard |
| 522 | Longest Uncommon Subsequence II | Medium |
| 1239 | Maximum Length of a Concatenated String with Unique Characters | Medium |
WEEK 18
| # | Title | Difficulty |
|---|---|---|
| DESIGN (SPECIAL TOPIC) | ||
| 706 | Design HashMap | Easy |
| 1656 | Design an Ordered Stream | Easy |
| 355 | Design Twitter | Medium |
| 707 | Design Linked List | Medium |
| 641 | Design Circular Deque | Medium |
| 622 | Design Circular Queue | Medium |
| 1396 | Design Underground System | Medium |
| 1472 | Design Browser History | Medium |
| 1797 | Design Authentication Manager | Medium |
| 2043 | Simple Bank System | Medium |
| 1993 | Operations on Tree | Medium |
| 2034 | Stock Price Fluctuation | Medium |
| 208 | Implement Trie (Prefix Tree) | Medium |
| 1912 | Design Movie Rental System | Hard |