Sets & Maps

Master hash-based data structures that provide O(1) lookups and are essential for solving a wide range of coding problems.

What You'll Learn

  • Hash Sets: Store unique values with fast membership testing
  • Hash Maps: Associate keys with values for counting, indexing, and grouping
  • Common patterns like frequency counting, complement finding, and sliding windows

These are among the most frequently used data structures in coding interviews.

NextHash Sets