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Solution: First Unique Character in a String

Understand how to track character frequencies with a hash map to find the first unique character in a string. This lesson teaches you to implement an efficient O(n) time solution with constant space, enhancing your ability to solve frequency-based coding problems.

Statement

For a given string of characters, s, your task is to find the first non-repeating character and return its index. Return 1-1 if there’s no unique character in the given string.

Constraints:

  • 11 \leq s.length ...