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