How should I practice Reverse Vowels of a String?

Start by reading the full statement, solve the visible examples, then compare the pattern against related Google onsite interview problems in FastPrep.

Is Reverse Vowels of a String associated with Google?

FastPrep tags this as a Google onsite interview coding practice problem when the problem catalog has that company and stage context.

Reverse Vowels of a String

Google● EasyNEW GRADONSITE INTERVIEW

Learn

Problem statement

Given a string s, reverse only its vowel characters and return the resulting string.

The vowels are a, e, i, o, and u, in either lowercase or uppercase. Preserve every vowel's original character and case while reversing their order. Every non-vowel character remains at its original index.

The string may be large, so avoid repeated string rebuilding that takes quadratic time.

Function

reverseVowels(s: String) → String

Examples

Example 1

s = "hello"return = "holle"

The vowels are e and o. Reversing them produces holle.

Example 2

s = "leetcode"return = "leotcede"

The vowel sequence e, e, o, e becomes e, o, e, e; consonants keep their positions.

Example 3

s = "aA"return = "Aa"

Uppercase and lowercase vowels both participate, and their original cases move with the characters.

Constraints

0 <= s.length <= 10^6.
s contains printable ASCII characters.