题目：

题解：

class Solution {public String reverseWords(String s) {StringBuffer ret = new StringBuffer();int length = s.length();int i = 0;while (i < length) {int start = i;while (i < length && s.charAt(i) != ' ') {i++;}for (int p = start; p < i; p++) {ret.append(s.charAt(start + i - 1 - p));}while (i < length && s.charAt(i) == ' ') {i++;ret.append(' ');}}return ret.toString();}
}