This Repository is aimed to help professional programmers/students improve problem solving and tackle basic concepts. The contents are based on questions that we have come across during our interview experiences.
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| Heap Problems | Difficulty | solution link |
|---|---|---|
| Leetcode Problem 21. Merge Two Sorted Lists | Easy | python |
| Leetcode Problem 23 Merge K Sorted Lists | Medium | python |
| Leetcode Problem 295 Find Median from Data Stream | Hard | python |
| Leetcode Problem 692 Top K Frequent Words | Medium | python |
| Leetcode Problem 703 Kth Largest Element in a Stream | Easy | python |
| Leetcode Problem 973. K Closest Points to Origin | Medium | python |
| Binary Search Problems | Difficulty | solution link |
|---|---|---|
| Leetcode Problem 4 Median of two sorted arrays | Hard | CSharp |
| Leetcode Problem 33. Search in Rotated Sorted Array | Medium | Python |
| Leetcode Problem 34. Find First and Last Position of Element in Sorted Array | Medium | CSharp |
| Leetcode Problem 74. Search a 2D Matrix | Medium | python |
| Leetcode Problem 162 Find Peak Element | Medium | CSharp |
| Dynamic Programming Problems | Difficulty | solution link |
|---|---|---|
| Leetcode Problem 44 Wildcard Matching | Hard | Python |
| Leetcode Problem 55. Jump Game | Medium | python |
| Leetcode Problem 62 Unique Paths | Medium | Python |
| Leetcode Problem 63 Unique Paths | Medium | Python |
| Leetcode Problem 64. Minimum Path Sum | Medium | Python |
| Leetcode Problem 70. Climbing Stairs | Easy | Python |
| Leetcode Problem 72 Edit Distance | Hard | Python |
| Leetcode Problem 85. Maximal Rectangle | Hard | Python |
| Leetcode Problem 139. Word Break | Medium | Python |
| Leetcode Problem 140. Word Break II | Hard | Python |
| Leetcode Problem 198 House Robber | Easy | Python |
| Leetcode Problem 221. Maximal Square | Medium | Python |
| Leetcode Problem 322 Coin Change | Medium | Python |
| Leetcode Problem 348. Design Tic-Tac-Toe | Medium | Python |
| Leetcode Problem 1143. Longest Common Subsequence | Medium | Python |
| Linked List Problems | Difficulty | solution link |
|---|---|---|
| Leetcode Problem 2 Add Two Numbers | Medium | Python |
| Leetcode Problem 19. Remove Nth Node From End of List | Medium | Python |
| Leetcode Problem 24. Swap Nodes in Pairs | Medium | Python |
| Leetcode Problem 82 Remove Duplicates from sorted list | Medium | CSharp |
| Leetcode Problem 92. Reverse Linked List II | Medium | Python |
| Leetcode Problem 141. Linked List Cycle | Medium | CSharp |
| Leetcode Problem 142. Linked List Cycle 2 | Medium | CSharp |
| Leetcode Problem 146. LRU Cache | Medium | Python |
| Backtracking Problems | Difficulty | solution link |
|---|---|---|
| Leetcode Problem 39. Combination Sum | Medium | CSharp |
| Leetcode Problem 51 N-Queens | Hard | CSharp |
| Leetcode Problem 72 Edit Distance | Hard | CSharp |
| Leetcode Problem 78. Subsets | Medium | Python |
| BFS DFS Problems | Difficulty | solution link |
|---|---|---|
| Leetcode Problem 79. Word Search | Medium | Python |
| Leetcode Problem 102. Binary Tree Level Order Traversal | Medium | Python |
| Leetcode Problem 103. Binary Tree Zigzag Level Order Traversal | Medium | Python |
| Leetcode Problem 130. Surrounded Regions | Medium | Python |
| Leetcode Problem 207 Course Schedule | Medium | Python |
| Leetcode Problem 210 Course Schedule II | Medium | Python |
| Leetcode Problem 289 Game of life | Medium | Python |
| Leetcode Problem 472. Concatenated Words | Hard | Python |
| Leetcode Problem 529. Minesweeper | Medium | Python |
| Leetcode Problem 733. Flood Fill | Easy | Python |
| Leetcode Problem 994 Rotting Oranges | Easy | Python |
| Two Pointer Problems | Difficulty | solution link |
|---|---|---|
| Leetcode Problem 3 Longest Substring Without Repeating Characters | Medium | Python |
| Leetcode Problem 5 Longest Palindrome Substring | Medium | Python |
| Leetcode Problem 27 Remove Element | Easy | Python |
| Leetcode Problem 15 3Sum | Medium | Python |
| Leetcode Problem 26. Remove Duplicates from Sorted Array | Easy | Python |
| Leetcode Problem 76. Minimum Window Substring | Hard | Python |
| Leetcode Problem 125 Valid Palindrome | Easy | Python |
| Leetcode Problem 680 Valid Palindrome II | Easy | Python |
| Trie Algorithm Based | Difficulty | solution link |
|---|---|---|
| Leetcode Problem 208. Implement Trie (Prefix Tree) | Medium | Python |
| Leetcode Problem 212. Word Search II | Medium | Python |
| Leetcode Problem 1233. Remove Sub-Folders from the Filesystem | Medium | Python |
| Hash maps and Arrays | Difficulty | solution link |
|---|---|---|
| Leetcode Problem 1. Two Sum | Easy | Python |
| Leetcode Problem 128. Longest Consecutive Sequence | Medium | Csharp |
| Leetcode Problem 138. Copy List with Random Pointer | Medium | Python |
| Leetcode Problem 340. Longest Substring with At Most K Distinct Characters | Hard | [Python] |
| Leetcode Problem 454. 4Sum II | Medium | Python |
| Sort | Difficulty | solution link |
|---|---|---|
| Leetcode Problem 75. Sort Colors | Medium | Python |
| Leetcode Problem 88. Merge Sorted Array | Medium | Python |
| Leetcode Problem 179. Largest Number | Medium | Python |
| Leetcode Problem 148. Sort List | Medium | Python |
| Leetcode Problem 253. Meeting Rooms II | Medium | [Python] |
| Leetcode Problem 315. Count of Smaller Numbers After Self | Hard | Python |
| Leetcode Problem 324. Wiggle Sort II | Medium | Python |
| Stack Problems | Difficulty | solution link |
|---|---|---|
| Leetcode Problem 20. Valid Parentheses | Easy | |
| Leetcode Problem 341. Flatten Nested List Iterator | Medium | Python |
| Math Problems | Difficulty | solution link |
|---|---|---|
| Leetcode Problem 74. Search a 2D Matrix | Medium | Python |
| Leetcode Problem 118. Pascal's Triangle | Easy | Python |
| Leetcode Problem 326. Power of Three | Easy | Python |
| Leetcode Problem 1362. Closest Divisors | Medium | Python |
| Leetcode Problem 1363. Largest Multiple of Three | Hard | Python |