Sliding Window
3 programs — patterns, complexity, and code
| # | Program Name | Pattern | Time | Space | Key Idea | Level |
|---|---|---|---|---|---|---|
| 1 | lengthOfLongestSubstring | Sliding Window + HashSet | O(n) | O(k) | Expand right; when duplicate found, shrink left until the window is valid. | Middle |
| 2 | maxSumSubarrayK | Fixed Sliding Window | O(n) | O(1) | Maintain a window of size k; slide by adding new element and dropping leftmost. | Simple |
| 3 | minWindowSubstring | Variable Sliding Window | O(n) | O(k) | Expand right to include all needed chars; shrink left while window is still valid. | Complex |