关于priority_queue,关于仿函数.

还是国外论坛找答案给力~ 唉~ http://stackoverflow.com/questions/7912595/initialization-for-stl-priority-queue

我太低端了  一直没搞懂priority_queue的第三个参数， 写了下终于懂了。

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


struct processor
{
    int        priority;
    string    name;
    processor(int _priority, string _name): priority(_priority), name(_name){};
    processor()
    {
        priority = 0;
        name = "-";
    }
};

struct comparator
{
    bool operator() (const processor& first, const processor& second)
    {
        return first.priority < second.priority;
    }
};

int main()
{
    priority_queue<processor, vector<processor>, comparator> process_queue;
    processor arr_pro[] = {processor(1000, "system"),
                           processor(10, "user"),
                           processor(100, "administrator"),
                           processor(999, "kevin")
                          };


    for(int i = 0; i < 4; i++)
    {
        process_queue.push(arr_pro[i]);
    }

    while(!process_queue.empty())
    {
        processor temp;
        temp = process_queue.top();
        process_queue.pop();
        cout << temp.name << '\t' << temp.priority << endl;
    }
    
}

* 也可以重载运算符 ‘<’

// functor.cpp : 定义控制台应用程序的入口点。
//

#include "stdafx.h"
#include <iostream>
#include <string>
#include <vector>
#include <queue>
using namespace std;


struct processor
{
    int        priority;
    string    name;
    processor(int _priority, string _name): priority(_priority), name(_name){};
    processor()
    {
        priority = 0;
        name = "-";
    }

    friend bool operator< (const processor& first, const processor& second)
    {
        return first.priority < second.priority;
    }
};

// struct comparator
// {
//     bool operator() (const processor& first, const processor& second)
//     {
//         return first.priority < second.priority;
//     }
// };

int main()
{
    //priority_queue<processor, vector<processor>, comparator> process_queue;
    priority_queue<processor> process_queue;
    processor arr_pro[] = {processor(1000, "system"),
                           processor(10, "user"),
                           processor(100, "administrator"),
                           processor(999, "kevin")
                          };


    for(int i = 0; i < 4; i++)
    {
        process_queue.push(arr_pro[i]);
    }

    while(!process_queue.empty())
    {
        processor temp;
        temp = process_queue.top();
        process_queue.pop();
        cout << temp.name << '\t' << temp.priority << endl;
    }
    
}