Two Pointers (Same Direction)

The Two Pointers (Same Direction) technique is applied when tackling problems characterized by specific invariants in the problem state or constraints:

• Core Strategy: A read/write or slow/fast pair of pointers moving the same direction through a sequence, compacting or scanning in place.
• 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 Two Pointers foundations, reducing worst-case algorithmic complexity.