（ACM模板）二元组pair

#include<iostream>
#include<cstdio>
#include<utility>
using namespace std;

typedef pair<string,int> P; 

int main()
{
    //pair类型定义以及赋值
    //pair用first访问第一个元素，second访问第二个元素
    pair<string,int> p1("Clno1",);
    pair<string,double> p2;
    p2.first="Clno1";
    p2.second=6.66;
    cout<<"p1:"<<p1.first<<" "<<p1.second<<endl;
    cout<<"p2:"<<p2.first<<" "<<p2.second<<endl;

    //用make_pair生成新的pair类型数据
    pair<string,int> p3;
    p3=make_pair("Clno1",);
    pair<string,int> p4=p3;
    cout<<"p3:"<<p3.first<<" "<<p3.second<<endl;
    cout<<"p4:"<<p4.first<<" "<<p4.second<<endl;

    //用typedef精简代码
    P p5=make_pair("Clno1",);
    cout<<"p5:"<<p5.first<<" "<<p5.second<<endl;

    return ;
}