1.描述

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".

Note:
The vowels does not include the letter "y".

2.分析

3.代码

class Solution {
public:
    string reverseVowels(string s) {
        if (s.size() == 0 || s.size() == 1) return s;
        int low = 0, high = s.size() - 1;
        while (low < high) {
            low = s.find_first_of("aeiouAEIOU", low);
            high = s.find_last_of("aeiouAEIOU", high);
            if (low < high) {
                swap(s[low++], s[high--]);
            }
        }
        return s;
    }
};