Noi2004郁闷的出纳员-treap树

 1 #include<iostream>
 2 #include<cstdlib>
 3 #include<cstdio>
 4 #include<algorithm>
 5 using namespace std;
 6 struct Node{
 7        int ch[2];
 8        int key,size,pri;
 9        void set(int x){ch[0]=ch[1]=0;key=x;size=1;pri=rand();}
10 }tree[1000000];
11 int tree_size,root,sum,all;
12 int n,minn;
13 void update(int v){
14      tree[v].size=1;
15      if(tree[v].ch[0]) tree[v].size+=tree[tree[v].ch[0]].size;
16      if(tree[v].ch[1]) tree[v].size+=tree[tree[v].ch[1]].size;
17 }
18 void rotate(int &v,int f){
19      int y=tree[v].ch[f];
20      tree[v].ch[f]=tree[y].ch[!f];
21      tree[y].ch[!f]=v;
22      update(v);update(y);
23      v=y;
24 }   
25 void insert(int &v,int x){
26      if(v==0){tree[v=++sum].set(x);}
27      else{
28           tree[v].size++;
29           int f=!(x<=tree[v].key);
30           insert(tree[v].ch[f],x); 
31           if(tree[v].pri<tree[tree[v].ch[f]].pri) rotate(v,f);
32      }
33 }
34 void del(int &v,int x){
35      if(tree[v].key==x){
36                         if(!tree[v].ch[0]||!tree[v].ch[1]){
37                                                            if(!tree[v].ch[0]) v=tree[v].ch[1];
38                                                            else v=tree[v].ch[0];
39                         }
40                         else{
41                              int f=!(tree[tree[v].ch[0]].pri>tree[tree[v].ch[1]].pri);
42                              rotate(v,f);
43                              tree[v].size--;
44                              del(tree[v].ch[!f],x);
45                         }
46      }
47      else{
48           tree[v].size--;
49           int f=(x<tree[v].key);
50           del(tree[v].ch[!f],x);
51      }
52 }  
53 int find(int v,int x){
54     if(x>tree_size||x<=0) return -1;
55     int mid=1;
56     if(tree[v].ch[0]) mid+=tree[tree[v].ch[0]].size;
57     if(x==mid) return tree[v].key+all;
58     if(x<mid) return find(tree[v].ch[0],x);
59     return find(tree[v].ch[1],x-mid);
60 }
61                 
62 int main()
63 {
64     char opt[2];
65     int k,decans=0;
66     scanf("%d %d",&n,&minn);
67     for(int i=0;i<n;i++){
68             scanf("%s %d",&opt,&k);
69             if(opt[0]==‘I‘&&k>=minn){insert(root,k-all);tree_size++;}
70             if(opt[0]==‘A‘){all+=k;}
71             if(opt[0]==‘S‘){
72                             all-=k;
73                             int tmp;
74                             while((tree_size>0) && ((tmp=find(root,1))<minn)){
75                                                                   tree_size--;
76                                                                   decans++;
77                                                                   del(root,tmp-all);
78                             }
79             }
80             if(opt[0]==‘F‘){printf("%d\n",find(root,tree_size+1-k));}
81     }
82     printf("%d\n",decans);
83 
84     return 0;
85 }