priority_queue里面自定义类型的使用。

 1 #include<iostream>
 2 #include<queue>
 3 using namespace std;
 4 struct tree{
 5     int num;
 6     string s;
 7     tree(int x,string zfc)
 8     {
 9         num=x;
10         s=zfc;
11     }
12     friend bool operator>(const tree &a,const tree &b)
13     {
14         return a.num>b.num;
15     }
16     /* 显然用不用友元来重载是不一样滴*/ 
17     /*bool operator<(const tree &a)const
18     {
19         return a.num>num;
20     }*/
21     bool operator==(const tree &a)const
22     {
23         return a.num>num;
24     }
25 };
26 /* 两个重载的<，随便一个都可以,显然里面和外面重载参数个数是不同滴*/
27 bool operator<(tree a,tree b)
28 {
29     return a.s<b.s;
30 }
31 int main()
32 {
33     priority_queue<tree> q;
34     /* 因为要用到优先队列，所以必须重载<*/
35     tree t(5,"hh");
36     q.push(t);
37     tree r(4,"xx");
38     q.push(r);
39     while(!q.empty())
40     {
41         cout<<q.top().num<<" "<<q.top().s<<endl;
42         q.pop();
43     }
44     if(r==t)
45     cout<<"hh";
46     else
47     cout<<"xx";
48 }

 1 #include<iostream>
 2 #include<queue>
 3 using namespace std;
 4 typedef struct tree* T;
 5 struct tree{
 6     int num;
 7     string s;
 8     T next;
 9     tree(){
10     }
11     tree(int x,string zfc)
12     {
13         num=x;
14         s=zfc;
15     }
16     friend bool operator<(const tree a,const tree b)
17     {
18         return b.num>a.num;
19     }
20 };
21 struct cmp{
22     bool operator()(T a,T b)
23     {
24         return a->num>b->num;
25     }
26 }; /* 使用结构体重载排序函数，priority_queue中就必须写好3个参数*/
27 int main()
28 {
29 //    priority_queue<T,vector<T>,cmp> q;
30     priority_queue<T> q;/* 不知道为啥，这里创造优先队列，没有重载排序函数，它也没有报错了*/
31     T t=new tree();/* 指针类型必须分配空间*/
32     t->num=5;
33     t->s="hhh";
34     q.push(t);
35     T r=new tree();
36     r->num=4;
37     r->s="xxx";
38     q.push(r);
39     T h=new tree(3,"nn");
40     q.push(h);
41     while(!q.empty())
42     {
43         cout<<q.top()->num<<" "<<q.top()->s<<endl;
44         q.pop();
45     }
46 }