priority_queue队列问题，如何指定自己的优先级？

[luo6620378xu]

例如我定义了一个如下的结构体；

struct Node
{
int frequery;
int tr;
bool operator < (const Node &a) const
{
return (frequery<a.frequery);
}//我想自己去重载，编译器报错
};

int main()
{
priority_queue< Node> q;

Node w[10];
w[0].frequery=12;
w[1].frequery=32;
w[2].frequery=34;

q.push(w[0]);
q.push(w[1]);
q.push(w[2]);

while(!q.empty())
{
cout<<q.top().frequery<<" ";
q.pop();
}
cout<<endl;


return 0;
}

它默认的是按照frequery的降序输出的，我想要它按照升序输出。该怎编码？

[luo6620378xu]

自己顶!

[xuhb95083023]

把operator<去掉

// 函数对象
struct node_comp {
    bool operator()(const node& lhs, const node& rhs) const {
        return lhs.frequery < rhs.frequery;
    }
}

// 声明方法
std::prior_queue<node, node_comp> my_prior_queue;

[hityct1]

#include <iostream>
//#include <sstream>
//#include <cassert>
//#include <windows.h>
#include <vector>
#include <queue>

using namespace std;

//看看priority_queue的声明，模板的第三个参数就是比较规则，规则可以是个函数，也可是个仿函数
//template < class T, class Container = vector<T>,
//           class Compare = less<typename Container::value_type> > class priority_queue;
struct Node 
{ 
	int frequery; 
	int tr; 
	/*bool operator() (const Node& lhs, const Node& rhs) const
	{ 
		return (lhs.frequery > rhs.frequery); 
	}*/

	friend bool operator> (const Node& lhs, const Node& rhs)
	{
		return (lhs.frequery > rhs.frequery); 
	}
}; 

int main() 
{ 
	priority_queue < Node, vector<Node>, greater<Node> >  q; //仿函数greater中用到operator>

	Node w[10]; 
	w[0].frequery=12; 
	w[1].frequery=32; 
	w[2].frequery=34; 

	q.push(w[0]); 
	q.push(w[1]); 
	q.push(w[2]); 

	while(!q.empty()) 
	{ 
		cout <<q.top().frequery <<" "; 
		q.pop(); 
	} 
	cout <<endl; 


	return 0; 
} 

[hityct1]

二楼方法也可，不过需要改一下。

#include <iostream>
#include <vector>
#include <queue>

using namespace std;

//看看priority_queue的声明，模板的第三个参数就是比较规则，规则可以是个函数，也可是个仿函数
//template < class T, class Container = vector<T>,
//           class Compare = less<typename Container::value_type> > class priority_queue;
struct Node 
{ 
	int frequery; 
	int tr; 
	/*bool operator() (const Node& lhs, const Node& rhs) const
	{ 
		return (lhs.frequery > rhs.frequery); 
	}*/

	friend bool operator> (const Node& lhs, const Node& rhs)
	{
		return (lhs.frequery > rhs.frequery); 
	}
}; 

struct node_greater_comp {

    bool operator()(const Node& lhs, const Node& rhs) const 
	{
        return lhs.frequery > rhs.frequery;
    }
};

int main() 
{ 
	//示例一
	{
	priority_queue < Node, vector<Node>, greater<Node> >  q; //仿函数greater中用到operator>

	Node w[10]; 
	w[0].frequery=12; 
	w[1].frequery=32; 
	w[2].frequery=34; 

	q.push(w[0]); 
	q.push(w[1]); 
	q.push(w[2]); 

	while(!q.empty()) 
	{ 
		cout <<q.top().frequery <<" "; 
		q.pop(); 
	} 
	cout <<endl; 
	}

	//示例二
	{
	priority_queue < Node, vector<Node>, node_greater_comp >  q; //仿函数node_greater_comp是比较规则

	Node w[10]; 
	w[0].frequery=12; 
	w[1].frequery=32; 
	w[2].frequery=34; 

	q.push(w[0]); 
	q.push(w[1]); 
	q.push(w[2]); 

	while(!q.empty()) 
	{ 
		cout <<q.top().frequery <<" "; 
		q.pop(); 
	} 
	cout <<endl; 
	}

	return 0; 
} 

[mailczl]

可是一直想寻找如何遍历priority_queue的方法，都没有找到呢