345. Reverse Vowels of a String

Write a function that takes a string as input and reverse only the vowels of a string.

Example 1:
Given s = "hello", return "holle".

Example 2:
Given s = "leetcode", return "leotcede".

class Solution {
public:
    string reverseVowels(string s) {
        if (s.size() == 0)
            return s;
    
    
        int start = 0;
        int end = s.size() - 1;
        while (start < end)
        {
            while (!isVowel(s[start])) {
                ++start;
            }
            while (!isVowel(s[end])) {
                --end;
            }
            if(start<end)
            {
                char tmp = s[start];
                s[start] = s[end];
                s[end] = tmp;
                start++;
                end--;
            }
        }
        return s;
    }
    
    bool isVowel(char ch) {
        vector<char> cvec{ 'a','e','i','o','u' ,'A','E','I','O','U'};
        if (find(cvec.begin(), cvec.end(), ch) == cvec.end())
            return false;
        return true;
    }
};