C++ pair,map,vector简单用法

#include <iostream>
#include <vector>
#include <map>
using namespace std;
int main(){

	pair<int,double>  p1;
	p1 = std::make_pair(1,2.5);
	cout<<p1.first<<endl<<p1.second<<endl;

	pair<int,float> p2(2,4.56);
	cout<<p2.first<<endl<<p2.second<<endl;


	vector<int> v1 ;
	v1.push_back(1);
	v1.push_back(2);
	v1.push_back(3);
	v1.push_back(4);

        v1.pop_back();//删除最后一个元素，返回void
	int begin= v1.front();//返回第一个元素的值，不删除
	cout<<begin<<endl;

	map<int,char> m1 ;
	m1[0] = 'a';
	m1[1] = 'b';
	m1[2] = 'c';
	cout<<m1[2]<<endl;
return 0;
}

//1
//2.5
//2
//4.56
//1
//c
//请按任意键继续. . .

参考：

http://blog.csdn.net/u012787116/article/details/52064168

http://blog.csdn.net/hancunai0017/article/details/7032383