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Solution: First Unique Character in a String

Explore how to identify the first unique character in a string by tracking character frequencies with a hash map. Understand the approach to traverse the string twice for an efficient solution with linear time complexity and constant space usage. This lesson guides you through implementing and analyzing this common coding interview problem using JavaScript.

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 ...