题目描述
牛客最近来了一个新员工Fish，每天早晨总是会拿着一本英文杂志，写些句子在本子上。同事Cat对Fish写的内容颇感兴趣，有一天他向Fish借来翻看，但却读不懂它的意思。例如，“student. a am I”。后来才意识到，这家伙原来把句子单词的顺序翻转了，正确的句子应该是“I am a student.”。Cat对一一的翻转这些单词顺序可不在行，你能帮助他么？

package com.hk;import java.util.ArrayList;
import java.util.Stack;/*** @author hk* @version 1.0* @date 2020/4/2 0002 15:09*/public class Solution {public String ReverseSentence(String str) {if (str == null || str.trim().length() == 0) {return str;}else {Stack<String> stack = new Stack<>();String[] strarray = str.split(" ");String s1 = "";for (String s : strarray) {stack.push(s);}while (stack.size() != 0) {s1 += stack.pop() + " ";}String s2 = s1.substring(0, s1.length() - 1);return s2;}}
}