【转载】c++常用排序规则，以及优先队列记录

#include<algorithm>
#include<iostream>
#include<vector>
#include<queue>
using namespace std;


bool cmp1(int a,int b)
{
    
    
    return a > b;
}

struct number1
{
    
    
    int a;
    number1(){
    
    }
    number1(int a):a(a){
    
    }
    bool operator < (const number1 & k) const{
    
    
        return a < k.a; //降序
    }
};


struct number2
{
    
    
    int a;
    number2(){
    
    }
    number2(int a):a(a){
    
    }
    bool operator < (const number2 & k) const{
    
    
        return a > k.a; //升序
    }
};


struct number3
{
    
    
    int a;
    number3(){
    
    }
    number3(int a):a(a){
    
    }
};


bool cmp2(number3 & a,number3 & b)
{
    
    
    return a.a < b.a;
}

struct cmp3
{
    
    
    bool operator () (const number3& a, const number3& b) const {
    
    
        return a.a < b.a;
    }
};

struct cmp4
{
    
    
    bool operator () (const int& a, const int& b) const {
    
    
        return a > b;
    }
};

int main()
{
    
    
    int a[10] = {
    
    9,8,23,25,5,1,6,4,1,4};
    sort(a, a + 10);//默认升序
    printf("a up\n");
    for(auto b : a) cout << b << ' ';
    cout << endl;
    sort(a, a + 10,cmp1); //自定义降序
    printf("a down\n");
    for(auto b : a) cout << b << ' ';
    cout << endl;
    number1 n1[10];
    number2 n2[10];
    number3 n3[10];
    for(int i = 0;i <  10;i++) {
    
    
        n1[i] = number1(a[i]);
        n2[i] = number2(a[i]);
        n3[i] = number3(a[i]);
    }
    sort(n1, n1 + 10);
    sort(n2, n2 + 10);
    sort(n3, n3 + 10,cmp2);
    printf("numbe1 \n");
    for(auto n : n1) cout << n.a << ' ';
    cout << endl;
    printf("numbe2 \n");
    
    for(auto n : n2) cout << n.a << ' ';
    cout << endl;
    printf("numbe3 \n");

    for(auto n : n3) cout << n.a << ' ';
    cout << endl;
    printf("priority_queue a 1\n");

    priority_queue<int> q1;
    for(auto b : a) q1.push(b);
    while(q1.size()) {
    
    
        cout << q1.top() << ' ';
        q1.pop();
    }
    cout << endl;


    printf("priority_queue a 2\n");

    priority_queue<int,vector<int>, cmp4> q;
    for(auto b : a) q.push(b);
    while(q.size()) {
    
    
        cout << q.top() << ' ';
        q.pop();
    }
    cout << endl;
    
    printf("priority_queue number2\n");

    priority_queue<number2> q2;
    for(auto n : n2) q2.push(n);
    while(q2.size()) {
    
    
        cout << q2.top().a << ' ';
        q2.pop();
    }
    cout << endl;

    printf("priority_queue number3\n");

    priority_queue<number3,vector<number3> ,cmp3> q3;
    for(auto n : n3) q3.push(n);
    while(q3.size()) {
    
    
        cout << q3.top().a <<  ' ';
        q3.pop();
    }
    cout << endl;

}

附上一个更为详细的优先队列排序讲解链接：https://blog.csdn.net/qq_40691051/article/details/102874220