# 0345. Reverse Vowels of a String
###### tags: `Leetcode` `Easy` `Two Pointers`
Link: https://leetcode.com/problems/reverse-vowels-of-a-string/description/

## Code
str是不能变更的数据结构 如果需要变更 先把它转成list ```s=list(s)``` 然后最后再把字母用```''.join(s)```合并成str

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