HDU-1062，Text Reverse（字符串处理 and 栈）

Problem Description：

Ignatius likes to write words in reverse way. Given a single line of text which is written by Ignatius, you should reverse all the words and then output them. 

Input： 

The input contains several test cases. The first line of the input is a single integer T which is the number of test cases. T test cases follow.
Each test case contains a single line with several words. There will be at most 1000 characters in a line. 

Output： 

For each test case, you should output the text which is processed. 

Sample Input： 

3

olleh !dlrow

m'I morf .udh

I ekil .mca 

Sample Output： 

hello world!

I'm from hdu.

I like acm. 

解题思路： 

看到题目，相信大家应该知道这道题就是字符串逆置，我们可以考虑将其存入栈中，然后依次输出就可以了，题目的要求是完全符合栈的“先进后出，后进先出”的特点的。剩下的我们看代码↓↓↓ 

程序代码： 

#include<iostream>
#include<cstdio>
#include<cstring>
#include<stack>
using namespace std;
int main()
{
	int n;
	char ch;
	scanf("%d",&n);
	getchar();//吸收回车符 
	while(n--)
	{
		stack<char> s;//定义一个栈 
		while(1)
		{
			ch=getchar();//每次读入一个字符 
			if(ch==' '||ch=='\n'||ch==EOF)//三个特殊的字符 
			{
				while(!s.empty())//栈不为空 
				{
					printf("%c",s.top());//输出此时的栈顶元素 
					s.pop();//清除栈顶元素 
				}
				if(ch=='\n'||ch==EOF)//结束条件 
					break;
				printf(" ");//记得每个单词（除了最后一个）后面都有一个空格 
			}
			else
				s.push(ch);//将这个字符压入栈 
		}
		printf("\n");
	}
	return 0;
}