Goat Latin

class Solution {
    public String toGoatLatin(String S) {
        String[] words=S.split(" ");
        StringBuilder res = new StringBuilder();

        for(int i = 0; i < words.length; i++){
            res.append(process(words[i]));
            for(int j = 0; j < i + 1; j++)
                res.append("a");

            if(i != words.length - 1)
                res.append(" ");
        }

        return res.toString();
    }

    public String process(String word) {
        if(isVowel(word.charAt(0))) {
            return word + "ma";
        } else {
            return word.substring(1) + word.charAt(0) + "ma";
        }
    }

    public boolean isVowel(char c) {
        return c == 'a' || c == 'A' || c == 'e' || c == 'E' || c == 'i' || c == 'I' || c == 'o' || c == 'O' || c == 'u' || c == 'U';
    }
}
#Status: Solved