A mistake that makes you humble is better than achievement that makes you arrogant.
🚧My Leetcode algorithm question practice solution using C# (.Net Core) and tested with MSUnit. Hope it would help anyone with their technical interviews or inspires someone who is simply interested in algorithms just like me.
| # | Question | Solution | Difficulty | Tag | Time Complexity | Space Complexity |
|---|---|---|---|---|---|---|
| 3 | ⭐ Longest Substring Without Repeating Characters | C# | Medium | Two Pointers, Sliding Window |
O(n) | O(1) |
| 15 | ⭐ 3Sum | C# | Medium | Two Pointers |
O(n^2) | O(1) |
| 16 | 3Sum Closest | C# | Medium | Two Pointers |
O(n^2) | O(1) |
| 75 | ⭐ Sort Colors | Medium | Two Pointers |
O(n) | O(1) | |
| 80 | ⭐ Remove Duplicates from Sorted Array II | C# | Medium | Two Pointers |
O(n) | O(1) |
| 88 | Merge Sorted Array | C# | Easy | Two Pointers |
O(n) | O(1) |
| 141 | Linked List Cycle | C# | Easy | Two Pointers, HashTable |
O(n) | O(1) |
| 167 | Two Sum II - Input array is sorted | C# | Easy | Two Pointers |
O(n) | O(1) |
| 209 | Minimum Size Subarray Sum | C# | Medium | Two Pointers |
O(n) | O(1) |
| 215 | Kth Largest Element in an Array | C# | Medium | Sorting, Priority Queue |
O(NLogK) | O(1) |
| 345 | Reverse Vowels of a String | C# | Easy | Two Pointers |
O(n) | O(1) |
| 347 | Top K Frequent Elements | C# | Medium | Bucket Sort |
O(n) | O(n) |
| 424 | ⭐⭐Longest Repeating Character Replacement | C# | Medium | Sliding Window, Two Pointers |
O(n) | O(26) |
| 451 | Sort Characters By Frequency | C# | Medium | Bucket Sort |
O(n) | O(n) |
| 524 | Longest Word in Dictionary through Deleting | C# | Medium | Two Pointers |
O(n^2) | O(1) |
| 633 | Sum of Square Numbers | C# | Easy | Two Pointers |
O(n) | O(1) |
| 680 | Valid Palindrome II | C# | Easy | Two Pointers |
O(n) | O(1) |
| 1200 | Minimum Absolute Difference | C# | Easy | Two Pointers |
O(nlogn + n) | O(1) |
| # | Question | Solution | Difficulty | Tag | Time Complexity | Space Complexity |
|---|---|---|---|---|---|---|
| 3 | ⭐ Longest Substring Without Repeating Characters | C# | Medium | Two Pointers, Sliding Window |
O(n) | O(1) |
| 15 | ⭐ 3Sum | C# | Medium | Two Pointers |
O(n^2) | O(1) |
| 16 | 3Sum Closest | C# | Medium | Two Pointers |
O(n^2) | O(1) |
| 75 | ⭐ Sort Colors | C# | Medium | Two Pointers |
O(n) | O(1) |
| 80 | ⭐ Remove Duplicates from Sorted Array II | C# | Medium | Two Pointers |
O(n) | O(1) |
| 88 | Merge Sorted Array | C# | Easy | Two Pointers |
O(n) | O(1) |
| 141 | Linked List Cycle | C# | Easy | Two Pointers, HashTable |
O(n) | O(1) |
| 167 | Two Sum II - Input array is sorted | C# | Easy | Two Pointers |
O(n) | O(1) |
| 209 | Minimum Size Subarray Sum | C# | Medium | Two Pointers |
O(n) | O(1) |
| 345 | Reverse Vowels of a String | C# | Easy | Two Pointers |
O(n) | O(1) |
| 424 | ⭐⭐Longest Repeating Character Replacement | C# | Medium | Sliding Window, Two Pointers |
O(n) | O(26) |
| 524 | Longest Word in Dictionary through Deleting | C# | Medium | Two Pointers |
O(n^2) | O(1) |
| 633 | Sum of Square Numbers | C# | Easy | Two Pointers |
O(n) | O(1) |
| 680 | Valid Palindrome II | C# | Easy | Two Pointers |
O(n) | O(1) |
| 1200 | Minimum Absolute Difference | C# | Easy | Two Pointers |
O(nlogn + n) | O(1) |
| # | Question | Solution | Difficulty | Tag | Time Complexity | Space Complexity |
|---|---|---|---|---|---|---|
| 215 | Kth Largest Element in an Array | C# | Medium | Sorting, Priority Queue |
O(NLogK) | O(1) |
| 347 | Top K Frequent Elements | C# | Medium | Bucket Sort |
O(n) | O(n) |
| 451 | Sort Characters By Frequency | C# | Medium | Bucket Sort |
O(n) | O(n) |