P3378【模板】 堆

 1 #include<iostream>
 2 #include<cstdio>
 3 using namespace std;
 4 
 5 int N;
 6 int operate;
 7 int x;
 8 int heap[1000000];
 9 int heap_size;
10 void put(int x) //插入一個數 
11 {
12     int now,next;
13     heap[++heap_size]=x;    //在末端插入 
14     now=heap_size;
15     while(now>1
 
)    //如果小於父節點就交換 
16     {
17         next=now>>1;
18         if(heap[now]>=heap[next]) return;   //退出 
19         swap(heap[now],heap[next]);
20         now=next;
21     }
22 }
23 
24 int del(int x)      //刪除一個數 
25 {
26     int now,next,res;
27     res=heap[1];    //heap[1]為堆頂；
28     heap[1]=heap[heap_size--];
 
29     now=1;
30     while(now * 2<=heap_size)
31     {
32         next=now * 2;   //左節點 
33         if(next<heap_size && heap[next+1]<heap[next])   //如果有右節點且右節點小   
34         {next++;}   
35         if(heap[now]<=heap[next])   {break;}        //退出 
36         swap(heap[now],heap[next]);
 
37         now=next;
38      } 
39      return res;
40 }
41 
42 int top()
43 {
44     return heap[1];
45 }
46 
47 int main()
48 {
49     scanf("%d",&N);
50     for(int i=1;i<=N;i++)
51     {
52         scanf("%d",&operate);
53         if(operate==1)
54         {
55             scanf("%d",&x);
56             put(x);
57         }
58         if(operate==2)
59         {
60             printf("%d\n",top());
61         }
62         if(operate==3)
63         {
64             del(1);
65         }
66     }
67 
68     return 0;
69 }

有stl為什麼不用呢？

 1 #include<iostream>
 2 #include<cstdio>
 3 #include<algorithm>
 4 #include<queue>
 5 using namespace std; 
 6 
 7 priority_queue<int,vector<int>,greater<int> >q;
 8 
 9 int main()
10 {
11     int n;
12     scanf("%d",&n);
13     for(int i=1;i<=n;i++)
14     {
15         int x;
16         scanf("%d",&x);
17         if(x==1) 
18         {
19             scanf("%d",&x);q.push(x);
20         }
21         else if(x==2) printf("%d\n",q.top());
22         
23         else q.pop();
24                
25     }   
26 }