codewars #62 Simple Pig Latin (5kyu)

#62 Simple Pig Latin

 to the end of it, then add "ay" to the end of the word. Leave punctuation marks untouched.

Examples

pigIt('Pig latin is cool'); // igPay atinlay siay oolcay

pigIt('Hello world !');     // elloHay orldWay !

import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class pigLatin {
	private static String leftShift(String s, int k) {
		k = k % s.length();
		return s.substring(k) + s.substring(0, k) + "ay";
	}

	public static String pigIt(String str) {
		Pattern p = Pattern.compile("([a-zA-Z]{1,})");
		Matcher m = p.matcher(str);
		StringBuffer sb = new StringBuffer();
		while (m.find()) {
			m.appendReplacement(sb, leftShift(m.group(), 1));
		}
		m.appendTail(sb);
		return sb.toString();
	}
}

가장 추천을 많이 받은 풀이

public class pigLatin {
    public static String pigIt(String str) {
        return str.replaceAll("(?i)([a-z])([a-z]*)", "$2$1ay");
    }
}