toj 2196 优先队列和堆的用法

 1 #include <iostream>
 2 #include <queue>
 3 using namespace std;
 4 
 5 //greater对int来说表示值越小优先级越高，也可以自己定义比较函数
 6 priority_queue< int, vector<int>, greater<int> > q;
 7 char op[2];
 8 
 9 int main ()
10 {
11     int n;
12     while ( cin >> n, n )
13     {
14         while ( n-- )
15         {
16             cin >> op;
17             if ( op[0] == ‘B‘ )
18             {
19                 int tmp;
20                 cin >> tmp;
21                 q.push(tmp);
22             }
23             else if ( op[0] == ‘G‘ )
24             {
25                 cout << q.top() << endl;                
26                 q.pop();
27             }
28         }
29         while ( !q.empty() )
30         {
31             q.pop();
32         }
33     }
34     return 0;
35 }

 1 //make_heap函数的用法类似下面两个函数
 2 #include <algorithm>
 3 #include <iostream>
 4 using namespace std;
 5 
 6 const int N = 100000;
 7 int heap[N];
 8 char op[2];
 9 int cnt;
10 
11 bool cmp( int a, int b )
12 {
13     return a > b;
14 }
15 
16 int main ()
17 {
18     int n;
19     while ( cin >> n, n )
20     {
21         cnt = 0;
22         while ( n-- )
23         {
24             cin >> op;
25             if ( op[0] == ‘B‘ )
26             {
27                 int tmp;
28                 cin >> tmp;
29                 //push_heap
30                 //注意push的用法，要先手动加入heap再调用
31                 heap[cnt++] = tmp;
32                 push_heap( heap, heap + cnt, cmp );
33             }
34             else if ( op[0] == ‘G‘ )
35             {
36                 //pop_heap
37                 //注意pop的用法，pop只是将堆顶的元素放到了heap最末尾的位置
38                 pop_heap( heap, heap + cnt, cmp );
39                 cnt--;
40                 cout << heap[cnt] << endl;
41             }
42         }
43     }
44     return 0;
45 }