Coding (Algo)

Count Matching Pairs

Algorithm: Hash map Difficulty: Easy Time: 25 minutes

Goal

Return the number of index pairs i < j for which nums[i] + nums[j] equals target.

What this task practices

Count Matching Pairs is a coding (algo) interview exercise that trains prompt interpretation, explicit assumptions, a concrete response, and a clear explanation of tradeoffs. The catalog marks it as easy difficulty. It focuses on Technical Reasoning, Testing, Validation. The signed-in workspace provides the tools for the round and evaluates the attempt against task-specific criteria. Reference solutions, hidden checks, evaluator instructions, and candidate work remain private.