#include <bits/stdc++.h>
#include <queue>

using namespace std;

struct temp1 //运算符重载<
{
    int x;
    temp1(int a) {x = a;}
    bool operator<(const temp1& a) const
    {
        return x < a.x;
    }
};

struct temp2 //重写仿函数
{
    bool operator() (temp1 a, temp1 b) 
    {
        return a.x < b.x; //'<'大顶堆 '>'小根堆
    }
};

int main()
{
    //对于基本类来说 默认是大根堆
    priority_queue<int> a;
    //等同于 priority_queue<int, vector<int> less<int> > a;

    //                                    这里一定要空格
    priority_queue<int, vector<int>, greater<int> > c;//小根堆
    priority_queue<string> b;

    for(int i = 0; i < 5; i ++)
    {
        a.push(i);
        c.push(i);
    }

    while(!a.empty())
    {
        cout<<a.top()<<' ';
        a.pop();
    }

    cout<<endl;

    while(!c.empty())
    {
        cout<<c.top()<<' ';
        c.pop();
    }

    cout<<endl;

    b.push("abc");
    b.push("abcd");
    b.push("cbd");

    while(!b.empty())
    {
        cout<<b.top()<<' ';
        b.pop();
    }

    cout<<'\n'<<endl;

    cout<<"pair 写优先队列"<<endl;
    //pair 写优先队列
    priority_queue<pair<int, int> >aa;
    pair<int, int> bb(1, 2);
    pair<int, int> cc(1, 3);
    pair<int, int> dd(2, 5);
    aa.push(dd);
    aa.push(cc);
    aa.push(bb);
    while(!aa.empty())
    {
        cout<<aa.top().first<<' '<<aa.top().second<<'\n';
        aa.pop();
    }

    cout<<'\n'<<endl;

    cout<<"用自定义类型做优先队列元素的例子"<<endl;

    temp1 aaa(1);
    temp1 bbb(2);
    temp1 ccc(3);

    priority_queue<temp1> ddd;

    ddd.push(bbb);
    ddd.push(ccc);
    ddd.push(aaa);

    while(!ddd.empty())
    {
        cout<<ddd.top().x<<'\n';
        ddd.pop();
    }

    cout<<endl;

    priority_queue<temp1, vector<temp1>, temp2> f;
    f.push(bbb);
    f.push(ccc);
    f.push(aaa);
    while(!f.empty())
    {
        cout<<f.top().x<<'\n';
        f.pop();
    }
    return 0;
}