LeetCode - Reverse Vowels of a String

Question

Link : https://leetcode.com/problems/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 “hole”.

Example 2:
Given s = “leetcode”, return “leotcede”.

Code

这个问题可以看做是上一个反转字符串的升级版—— LeetCode - Reverse String，我们可以利用那个里面第三种实现方法，加以改进判断一下是不是元音字母再交换位置即可。 （C++ : 12ms）

class Solution {
public:
    string reverseVowels(string s) {
        int start = 0, end = s.size() - 1;
        while(true){
            while(!isVowel(s[start]) && start < s.size())
                start++;
            while(!isVowel(s[end]) && end >= 0)
                end--;
            if(start < end)
                swap(s[start++], s[end--]);
            else
                break;
        }
        return s;
    }

    bool isVowel(char ch){
        return ch == 'a' || ch == 'e' || ch == 'i' || ch == 'o' || ch == 'u'
            || ch == 'A' || ch == 'E' || ch == 'I' || ch == 'O' || ch == 'U';
    }
};