[Solved] Given a string s, reverse only all the vowels in the string and return it.

Question

Given a string s, reverse only all the vowels in the string and return it.

The vowels are 'a', 'e', 'i', 'o', and 'u', and they can appear in both cases.

Example 1:

Input: s = "hello"
Output: "holle"

Example 2:

Input: s = "leetcode"
Output: "leotcede"

Constraints:

• 1 <= s.length <= 3 * 105
• s consist of printable ASCII characters.

Python Solution

class Solution:
    def reverseVowels(self, s: str) -> str:
        s=list(s)
        vowels = set(list('aeiouAEIOU'))
        l=0
        r=len(s)-1

        while l<r:
            if s[l] in vowels and s[r] in vowels:
                s[l],s[r] = s[r],s[l]
                l+=1
                r-=1
            if s[l] not in vowels:
                l+=1
            if s[r] not in vowels:
                r-=1
        return (''.join(s))