#include <iostream>
#include <bits/stdc++.h>
using  namespace  std;
struct VecCmp{bool operator()(int& a,int& b){return a>b;/*** 对于vector和list容器，这里写了＞就是从大到小* 对于priority_queue容器，这里写了>就是从小到大！*/}
};int main(){vector<int> v={5,6,7,8,9,1,2,3,4};cout<<"Vector Element = ";for(auto i:v){cout<<i<<" ";}cout<<endl;sort(v.begin(),v.end(),VecCmp());cout<<"VecCmp Sort-----------------------------------------"<<endl;for(auto i:v){cout<<i<<" ";}cout<<endl;cout<<"-----------------------------------------------------"<<endl;list<int> l={5,6,7,8,9,1,2,3,4};cout<<"List Element = ";for(auto i:l){cout<<i<<" ";}l.sort();cout<<endl;cout<<"Default list sort-------------------------------------------"<<endl;for(auto i:l){cout<<i<<" ";}cout<<"\nVecCmp sort----------------------------------------------------"<<endl;l.sort(VecCmp());for(auto i:l){cout<<i<<" ";}cout<<endl;return 0;
}

定义了priority_queue就不一样的代码是

#include <bits/stdc++.h>
using  namespace  std;
pair<int,int> p;
class Stu{
public:int age;int grade;Stu(int age,int grade){this->age=age;this->grade=grade;}friend ostream& operator<<(ostream & o,const Stu& s){o<<"[age = "<< s.age <<", grade = "<<s.grade<<" ]";o<<endl;return  o;}
};
struct less1{bool operator()(const Stu& s1,const Stu& s2)const{return s1.age>s2.age;}
};int main(){priority_queue<Stu,vector<Stu>,less1> pq;for(int i=0;i<10;++i){pq.emplace(i+18,i);}for (int i = 0; i < 10; ++i) {cout<<pq.top();pq.pop();}
}