LeetCode: Reverse Words in a String

/**
 * 
 */
package solution;

/**
 * @author whh
 * 
 *         Given an input string, reverse the string word by word. For example,
 *         Given s = "the sky is blue", return "blue is sky the".
 */
public class ReverseWordsInAString {

    /**
     * @param args
     */
    public static void main(String[] args) {
        String s = "  the     sky is  blue ";
        System.out.println(s);
        System.out.print(reverseWords(s));
    }

    /**
     * @param s
     * @return
     */
    public static String reverseWords(String s) {
        s = s.replaceAll(" +", " ");
        String[] s_array = s.split(" ");
        StringBuilder builder = new StringBuilder();
        for (int i = s_array.length - 1; i > -1; i--) {
            builder.append(s_array[i]);
            builder.append(" ");
        }

        return builder.toString().trim();
    }
}