Linked ListEvidence Contributing
Fast/Slow Pointers (Cycle & Midpoint)
A tortoise-and-hare pair of pointers moving at different speeds to detect a cycle or find a midpoint/kth-from-end node.
Practice Problems: 7
Difficulty: 2 Easy·5 Medium·0 Hard
Algorithmic Intuition & Recognition
The Fast/Slow Pointers (Cycle & Midpoint) technique is applied when tackling problems characterized by specific invariants in the problem state or constraints:
- Core Strategy: A tortoise-and-hare pair of pointers moving at different speeds to detect a cycle or find a midpoint/kth-from-end node.
- When to use: Look for opportunities where repeated re-computation can be replaced by maintaining monotonic properties, state windows, or relational pointers.
- Interview Signal: Demonstrating this pattern shows mastery of Linked List foundations, reducing worst-case algorithmic complexity.