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".

一刷
题解：
与344类似，不过这回只有元音字母需要交换位置，方法相同，two pointer

public class Solution {
    public String reverseVowels(String s) {
        char[] vowals = "aeiouAEIOU".toCharArray();
        char[] ss = s.toCharArray();
        Set dict = new HashSet();
        for(char a : vowals){
            dict.add(a);
        }
        int l = 0, r = s.length()-1;
        while(l

二刷
思路同上