（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 ;

}