Two Pointers¶
| Problem | Complexity | Key Pattern |
|---|---|---|
| Container With Most Water | O(n) |
Maximizing area/product with two boundaries — shrink from both ends, |
| Three Sum | O(n^2) |
Reducing N-sum to 2-sum on a sorted array — "find triplets/k-tuples |
| Trapping Rain Water | O(n) |
Bounded accumulation between barriers — water trapping, histogram |