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。

 1 #include <iostream>
 2 #include <string>
 3 #include <vector>
 4 #include <queue>
 5 using namespace std;
 6 
 7 
 8 struct processor
 9 {
10     int        priority;
11     string    name;
12     processor(int _priority, string _name): priority(_priority), name(_name){};
13     processor()
14     {
15         priority = 0;
16         name = "-";
17     }
18 };
19 
20 struct comparator
21 {
22     bool operator() (const processor& first, const processor& second)
23     {
24         return first.priority < second.priority;
25     }
26 };
27 
28 int main()
29 {
30     priority_queue<processor, vector<processor>, comparator> process_queue;
31     processor arr_pro[] = {processor(1000, "system"),
32                            processor(10, "user"),
33                            processor(100, "administrator"),
34                            processor(999, "kevin")
35                           };
36 
37 
38     for(int i = 0; i < 4; i++)
39     {
40         process_queue.push(arr_pro[i]);
41     }
42 
43     while(!process_queue.empty())
44     {
45         processor temp;
46         temp = process_queue.top();
47         process_queue.pop();
48         cout << temp.name << '\t' << temp.priority << endl;
49     }
50     
51 }

* 也可以重载运算符 ‘<’

 1 // functor.cpp : 定义控制台应用程序的入口点。
 2 //
 3 
 4 #include "stdafx.h"
 5 #include <iostream>
 6 #include <string>
 7 #include <vector>
 8 #include <queue>
 9 using namespace std;
10 
11 
12 struct processor
13 {
14     int        priority;
15     string    name;
16     processor(int _priority, string _name): priority(_priority), name(_name){};
17     processor()
18     {
19         priority = 0;
20         name = "-";
21     }
22 
23     friend bool operator< (const processor& first, const processor& second)
24     {
25         return first.priority < second.priority;
26     }
27 };
28 
29 // struct comparator
30 // {
31 //     bool operator() (const processor& first, const processor& second)
32 //     {
33 //         return first.priority < second.priority;
34 //     }
35 // };
36 
37 int main()
38 {
39     //priority_queue<processor, vector<processor>, comparator> process_queue;
40     priority_queue<processor> process_queue;
41     processor arr_pro[] = {processor(1000, "system"),
42                            processor(10, "user"),
43                            processor(100, "administrator"),
44                            processor(999, "kevin")
45                           };
46 
47 
48     for(int i = 0; i < 4; i++)
49     {
50         process_queue.push(arr_pro[i]);
51     }
52 
53     while(!process_queue.empty())
54     {
55         processor temp;
56         temp = process_queue.top();
57         process_queue.pop();
58         cout << temp.name << '\t' << temp.priority << endl;
59     }
60     
61 }