Master the steps to efficiently track data, solve permutations, anagrams, and game design problems.

Coding

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The ultimate guide to the System Design Interview – developed by Meta & Google engineers. Master distributed system fundamentals, and practice with real-world interview questions & mock interviews.

System Design

The essential guide to API Design & Product Design Interviews – developed by FAANG engineers. Master product design fundamentals & get hands-on with real-world APIs.

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A battle-tested guide to Object Oriented Design Interviews – developed by FAANG engineers. Master OOD fundamentals & practice real-world interview questions.

Low Level Design Interview Using OOD Principles

Your essential EM Interview crash course. Learn strategies from FAANG hiring managers to demonstrate your leadership skills & experience to interviewers.

Engineering Management and Leadership Interviews

The ultimate guide to behavioral interviews. Developed by FAANG engineers. Use real-world questions, video recording, and structured strategies to get interview-ready in just a few hours.

Behavioral

# Statement

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

**Constraints:**

* $1 \leq$ `s.length` $\leq 10^{3}$
* Only lowercase English letters are accepted.
* There are no spaces in the string.

# Examples

Try to solve the First Unique Character in a String problem.

Problem: First Unique Character in a String

Statement

Examples

Problem: First Unique Character in a String

Statement

Examples