2019-02-14 Day40待提高

1.#### 反转字符串中的元音字母
编写一个函数，以字符串作为输入，反转该字符串中的元音字母。

示例 1:

输入: "hello"
输出: "holle"
示例 2:

输入: "leetcode"
输出: "leotcede"
说明:
元音字母不包含字母"y"。

class Solution {
public:
    string reverseVowels(string s) {
        
        vector< int > buffer ;
        
        for( int i = 0 ; i < s.size() ; i++ )
        {
            if( s[i] == 'a' || s[i] == 'e' || s[i] == 'i' || s[i] == 'o' || s[i] == 'u'|| s[i] == 'A' || s[i] == 'E' || s[i] == 'I' || s[i] == 'O' || s[i] == 'U')
            {
                buffer.push_back(i);
            }
        }
        
        int size = buffer.size();
        
        int head = 0, end = size -1 ;
        
        char temp ;
        while( head < end )
        {
            temp = s[buffer[head]];
            s[buffer[head]] = s[buffer[end]];
            s[buffer[end]] = temp;
            head ++ , end --;
        }
    
        return s;
        
    }
};