c++Primer5.5.2练习

练习5.21

#include "stdafx.h"
#include<iostream>
#include<string>
#include<vector>
using namespace::std; 
int main()
{ 
	string begin_string,second_string;
	int flag = 0;
	while (cin>> begin_string )
	{
		if (begin_string == second_string && begin_string[0]<='Z'&& begin_string[0] >= 'A')
		{
			flag = 1;
			cout << begin_string << endl;
			break;
		}
		else
		{
			second_string = begin_string;
			flag = 0;
		}
	}
	if (!flag)
	{
		cout << "没有任何单词" << endl;
	}
	system("pause");
	return 0;

}