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All questions/Coding/First Non-Repeating Character

First Non-Repeating Character

Easy

Coding

Asked at 1 company1ArraysSearchingMath

Also asked at

Problem

Given a string s, return the index of the first character that appears exactly once. If no such character exists, return -1.

Examples

Example 1

Inputs = "leetcode"Output0Why`'l'` appears once and is the first unique character.

Example 2

Inputs = "aabb"Output-1WhyNo character appears exactly once.

Constraints

`1 <= len(s) <= 10^5`
`s` contains lowercase English letters
Return `-1` if there is no answer

Problem

Given a string s, return the index of the first character that appears exactly once. If no such character exists, return -1.

Examples

Example 1

Inputs = "leetcode"Output0Why`'l'` appears once and is the first unique character.

Example 2

Inputs = "aabb"Output-1WhyNo character appears exactly once.

Constraints

`1 <= len(s) <= 10^5`
`s` contains lowercase English letters
Return `-1` if there is no answer

Practice Python

Python 3.10

Open on desktop for the full Python editor with syntax highlighting and autocomplete.

All questions/Coding/First Non-Repeating Character

First Non-Repeating Character

Easy

Coding

Asked at 1 company1ArraysSearchingMath

Also asked at

Problem

Given a string s, return the index of the first character that appears exactly once. If no such character exists, return -1.

Examples

Example 1

Inputs = "leetcode"Output0Why`'l'` appears once and is the first unique character.

Example 2

Inputs = "aabb"Output-1WhyNo character appears exactly once.

Constraints

`1 <= len(s) <= 10^5`
`s` contains lowercase English letters
Return `-1` if there is no answer

Problem

Given a string s, return the index of the first character that appears exactly once. If no such character exists, return -1.

Examples

Example 1

Inputs = "leetcode"Output0Why`'l'` appears once and is the first unique character.

Example 2

Inputs = "aabb"Output-1WhyNo character appears exactly once.

Constraints

`1 <= len(s) <= 10^5`
`s` contains lowercase English letters
Return `-1` if there is no answer

Practice Python

Python 3.10

Open on desktop for the full Python editor with syntax highlighting and autocomplete.

First Non-Repeating Character | Dataford Interview Questions - Dataford - Ace your Interview