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".

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

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解题思路：将元音字母调换位置

class Solution {
public:
    string reverseVowels(string s) {
        int dist[256]={0};
        dist['a']=1;dist['A']=1;
        dist['e']=1;dist['E']=1;
        dist['i']=1;dist['I']=1;
        dist['o']=1;dist['O']=1;
        dist['u']=1;dist['U']=1;
        int begin=0;
        int end=(int)s.size()-1;
        while(begin<end){
            while(begin<end && dist[s[begin]]==0)begin++;
            while(begin<end && dist[s[end]]==0)end--;
            swap(s[begin],s[end]);
            begin++;
            end--;
        }
        return s;
    }
};