public class Solution {
    /*
     * @param s: A string
     * @return: A string
     */
    public static String reverseWords(String s) {
        if(s==null || s.length() == 0)  return "";
        String[] array = s.split(" ");
        StringBuilder sb = new StringBuilder();
        for (int
 
 i = array.length - 1; i>=0; --i) {
            if(!array[i].equals("")){
                sb.append(array[i]).append(" ");
            }
        }
        return sb.toString();
    }
}

LintCode 53---翻轉字符串中的單詞