Two Pointers

Definitions

1. An algorithmic technique using two indices that traverse an array from different positions or at different speeds to solve problems in O(n) time instead of O(n²). Patterns include: converging pointers (from both ends), fast/slow pointers (cycle detection), and sliding window. A fundamental coding interview pattern.

   In plain English: Using two moving markers in an array to efficiently find pairs, detect cycles, or solve problems without nested loops.

   Example: "To find if a sorted array has a pair summing to target, use converging two pointers from both ends — O(n) instead of nested loops."

Related Terms

• Cell Array
• Data Structure
• System Design
• Operational Transform
• Topological Sort
• Dijkstra's Algorithm
• Dynamic Programming
• Sliding Window