1 /*
 2 手寫三叉堆 
 3 */
 4 #include<cstdio>
 5 #include<iostream>
 6 using namespace std;
 7 
 8 class heap3{
 9     private:
10         int heap[100001];
11         int heap_size;
12     public:
13         void put(int d);
14         int get();
15         int getsize();
16         void
 
 in(int x,int y);
17         void out(int n);
18 };
19 
20 heap3 m;
21 
22 void heap3::out(int n){
23     for(int k=1;k<=n;++k) cout<<heap[k]<<‘ ‘;
24 }
25 
26 void heap3::in(int x,int y){heap[x]=y;}
27 
28 void heap3::put(int d)
29 {
30     heap[++heap_size]=d;
31     int
 
 now=heap_size,next;
32     
33     while(now>1)
34     {
35         next=(now+1)/3;
36         if(heap[now]<=heap[next]) break;
37         swap(heap[now],heap[next]);
38         now=next;
39     }
40     
41     return;
42 }
43 
44 int heap3::getsize(){return heap_size;}
45 
46 int
 
 heap3::get(){
47     
48     int now=1,next;
49     int res=heap[1];
50     heap[1]=heap[heap_size--];
51     
52     while(now*3-1 <= heap_size)
53     {
54         next=now*3-1;
55         
56         if(next+1<=heap_size && heap[next+1]>heap[next]){
57             next++;
58             
59             if(next+1<=heap_size && heap[next+1]>heap[next]) next++;
60         }
61         else
62         if(next+2<=heap_size && heap[next+2]>heap[next]) next+=2;
63             
64         if(heap[now]>=heap[next]) break;
65         
66         swap(heap[now],heap[next]);
67         now=next;
68     }
69     return res;
70 }
71 
72 int main(){
73     int n,x;
74     scanf("%d",&n);
75     for(int i=1;i<=n;++i){
76         scanf("%d",&x);
77         m.put(x);
78     }
79     
80     for(int i=1;i<n;++i){
81         int k=m.getsize();
82         m.in(k,m.get());
83     }
84     
85     m.out(n);
86     
87     return 0;
88 }

解釋先鴿著

三叉堆實現堆排序