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Understanding the Two Pointers Pattern

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Understanding the Two Pointers Pattern

EDITOR BRIEF

The Two Pointers pattern uses two indices to scan arrays or strings efficiently, often from opposite ends or at different speeds. It can replace nested loops and reduce runtime from O(N^2) to O(N), or to O(N log N) when sorting is needed. It can also help with in-place changes using O(1) extra space.

INSIGHTS

This pattern is useful when brute force feels too slow on arrays or strings. A good next step is to practice finding where two indices can move together or toward each other in simple coding problems.

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