[LeetCode]--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”.

public String reverseVowels(String s) {
        char[] ss = s.toCharArray();
        int j = ss.length - 1, i = 0;
        char temp;
        while (i < j) {
            while (i < j && !isVowel(ss[i]))
                i++;
            while (i < j && !isVowel(ss[j]))
                j--;
            temp = ss[i];
            ss[i] = ss[j];
            ss[j] = temp;
            i++;
            j--;
        }
        return String.valueOf(ss);
    }

    public boolean isVowel(char c) {
        if (c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u')
            return true;
        if (c == 'A' || c == 'E' || c == 'I' || c == 'O' || c == 'U')
            return true;
        return false;
    }