STL之priority_queue

#include <iostream>
#include<functional>
#include <queue>

using namespace std;

struct Node{
int x;
Node( int a= 0):x(a) {}
friend bool operator<(Node a,Node b )
{
return a.x<b.x;//  使用">"则为小根堆
}
};

struct cmp
{
bool operator()(Node a,Node b)
{
return a.x<b.x;
}
};
int main(){

int data2[5]={1,3,7,-4,56};
/******方法一*/
priority_queue<int> big(data2,data2+5);
while(!big.empty())
{
cout<<big.top()<<' ';
big.pop();
}
cout<<endl;
/******方法二*/
priority_queue<int,vector<int>,cmp> little(data2,data2+5);
//priority_queue<int,vector<int>,greater<int>> little(data2,data2+5);
while(!little.empty())
{
cout<<little.top()<<' ';
little.pop();
}
cout<<endl;
/******方法三*/
Node data1[10];
for( int i= 0; i< 10; ++i )
data1[i]=Node(rand());
priority_queue<Node> q(data1,data1+10);//自定义大根模式
while( !q.empty() )
{
cout << q.top().x << ' ' ;
q.pop();
}
cout<<endl;
return 0;
}