Reverse Vowels of a String

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

Example 1:

Input: "hello"
Output: "holle"

Example 2:

Input: "leetcode"
Output: "leotcede"

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

解法：

双向指针解决，题目意思没说得很清，坑。

class Solution {
    public String reverseVowels(String s) {
        int len = s.length();
        if(len == 0) return "";
        int left = 0;
        int right = len-1;
        char[] c = s.toCharArray(); 
        while(left<right){
            if(isVowels(c[left]) && isVowels(c[right])){
                char tmp = c[left];
                c[left] = c[right];
                c[right] = tmp;
                left++;  //处理完要移位啊！
                right--; //处理完要移位啊！
            }else if(!isVowels(c[left])){
                left++;
            }else if(!isVowels(c[right])){
                right--;
            }
            
        }
        return String.valueOf(c);
    }
    
    public boolean isVowels(Character c){
        return c=='a'||c=='e'||c=='i'||c=='o'||c=='u'||c=='A'||c=='E'||c=='I'||c=='O'||c=='U';
    }
    
}