Linked Lists
3 programs — patterns, complexity, and code
| # | Program Name | Pattern | Time | Space | Key Idea | Level |
|---|---|---|---|---|---|---|
| 1 | reverseLinkedList | Iteration | O(n) | O(1) | Keep prev pointer; re-link each node to prev, then advance both pointers. | Simple |
| 2 | linkedListCycle | Fast / Slow Pointer | O(n) | O(1) | Fast pointer moves 2 steps, slow 1; they meet inside the cycle if one exists. | Simple |
| 3 | mergeTwoSortedLists | Two Pointer | O(n+m) | O(1) | Compare heads; attach the smaller one to result list, advance that pointer. | Simple |