模板——无旋Treap 

 1 #include "bits/stdc++.h"
 2 
 3 using namespace std;
 4 
 5 inline int read(){
 6     int s=0,k=1;char ch=getchar();
 7     while(ch<'0'|ch>'9') ch=='-'?k=-1:0,ch=getchar();
 8     while(ch>47&ch<='9') s=s*10+(ch^48),ch=getchar();
 9     return s*k;
10 }
11 
12 const int N=1e5+5,inf=0x7fffffff;
13 
14 #define size(t) (t?t->size:0)
15 
16 struct Treap{
17     Treap *son[2];
18     int fix,val,size;
19     Treap (int v){
20         size=1,val=v,fix=rand();
21         son[0]=son[1]=NULL;
22     }
23     inline void update(){
24         size=1+size(son[0])+size(son[1]);
25     }
26 }*root;
27 
28 typedef pair<Treap*,Treap*> D;
29 
30 inline Treap *merge(Treap *a,Treap *b){
31     if(!a||!b) return a?a:b;
32     if(a->fix<b->fix){
33         a->son[1]=merge(a->son[1],b);a->update();return a;
34     }else   {
35         b->son[0]=merge(a,b->son[0]);b->update();return b;
36     }
37 }
38 
39 inline D split(Treap *p,int k){
40     if(!p)  return D(NULL,NULL);
41     D y;
42     if(size(p->son[0])>=k) 
43         y=split(p->son[0],k),p->son[0]=y.second,p->update(),y.second=p;
44     else
45         y=split(p->son[1],k-1-size(p->son[0])),p->son[1]=y.first,p->update(),y.first=p;
46     return y;
47 }
48 
49 inline int get_rnk(int val){
50     int ret=0;
51     for(Treap *t=root;t;t=t->son[val>t->val])
52         if(t->val<val)  ret+=1+size(t->son[0]);
53     return ret;
54 }
55 
56 inline int findkth(int k){
57     D x=split(root,k-1);
58     D y=split(x.second,1);
59     Treap *ans=y.first;
60     root=merge(merge(x.first,ans),y.second);
61     return ans?ans->val:0;
62 }
63 
64 inline void insert(int val){
65     int k=get_rnk(val);
66     D x=split(root,k);
67     Treap *p=new Treap(val);
68     root=merge(merge(x.first,p),x.second);
69 }
70 
71 inline void erase(int val){
72     int k=get_rnk(val);
73     D x=split(root,k);
74     D y=split(x.second,1);
75     root=merge(x.first,y.second);
76 }
77 
78 int main(){    
79     freopen("phs.in","r",stdin);
80     freopen("phs.out","w",stdout);
81     srand(1228);
82     int m,opt,x;m=read();
83     while(m--){
84         opt=read(),x=read();
85         switch(opt)
86         {
87             case 1:insert(x);break;
88             case 2:erase(x);break;
89             case 3:printf("%d\n",get_rnk(x)+1);break;
90             case 4:printf("%d\n",findkth(x));break;
91             case 5:printf("%d\n",findkth(get_rnk(x)));break;
92             case 6:printf("%d\n",findkth(get_rnk(x+1)+1));break;
93         }
94     }
95 }

 

posted @ 2018-01-02 15:30  Troywar  阅读(153)  评论(0)  编辑  收藏  举报