CSE-201 · Lesson 4 of 4

Hash Maps & Frequency Counting

Name: Hash Maps & Frequency Counting
Uploaded: 2026-05-03T00:00:00.000Z
Duration: 9 min
Description: When (and when not) to reach for a hash map. Frequency counting patterns you'll reuse forever.

Nusrat J.9m

When (and when not) to reach for a hash map. Frequency counting patterns you'll reuse forever.

Note

Assignment: solve 'Two Sum' in three different ways.

Lesson resources

LeetCode: Two Sum

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