bzoj3224 Tyvj 1728 普通平衡树

  1 //It is made by wfj_2048~
  2 #include <algorithm>
  3 #include <iostream>
  4 #include <complex>
  5 #include <cstring>
  6 #include <cstdlib>
  7 #include <cstdio>
  8 #include <vector>
  9 #include <cmath>
 10 #include <queue>
 11 #include <stack>
 12 #include <map>
 13 #include <set>
 14 #define N (100010)
 15 #define il inline
 16 #define RG register
 17 #define ll long long
 18 #define File(s) freopen(s".in","r",stdin),freopen(s".out","w",stdout)
 19 
 20 using namespace std;
 21 
 22 int ch[N][2],cover[N],sz[N],val[N],del[N],st[N],Q,rt,top,tot;
 23 const double alpha=0.75;
 24 
 25 il int gi(){
 26     RG int x=0,q=1; RG char ch=getchar(); while ((ch<‘0‘ || ch>‘9‘) && ch!=‘-‘) ch=getchar();
 27     if (ch==‘-‘) q=-1,ch=getchar(); while (ch>=‘0‘ && ch<=‘9‘) x=x*10+ch-48,ch=getchar(); return q*x;
 28 }
 29 
 30 il void pushup(RG int x){
 31     sz[x]=sz[ch[x][0]]+sz[ch[x][1]]+(!del[x]);
 32     cover[x]=cover[ch[x][0]]+cover[ch[x][1]]+1; return;
 33 }
 34 
 35 il void dfs(RG int x){
 36     if (ch[x][0]) dfs(ch[x][0]);
 37     if (!del[x]) st[++top]=x;
 38     if (ch[x][1]) dfs(ch[x][1]);
 39     sz[x]=cover[x]=ch[x][0]=ch[x][1]=0;
 40     return;
 41 }
 42 
 43 il int divide(RG int l,RG int r){
 44     if (l>r) return 0; RG int mid=(l+r)>>1;
 45     ch[st[mid]][0]=divide(l,mid-1);
 46     ch[st[mid]][1]=divide(mid+1,r);
 47     pushup(st[mid]); return st[mid];
 48 }
 49 
 50 il void rebuild(RG int &x){ top=0,dfs(x),x=divide(1,top); return; }
 51 
 52 il int qrank(RG int x,RG int k){
 53     RG int res=1;
 54     while (x){
 55     if (k<=val[x]) x=ch[x][0];
 56     else res+=sz[ch[x][0]]+(!del[x]),x=ch[x][1];
 57     }
 58     return res;
 59 }
 60 
 61 il int find(RG int x,RG int k){
 62     while (x){
 63     if (!del[x] && k==sz[ch[x][0]]+1) return val[x];
 64     if (k<=sz[ch[x][0]]) x=ch[x][0];
 65     else k-=sz[ch[x][0]]+(!del[x]),x=ch[x][1];
 66     }
 67     return val[x];
 68 }
 69 
 70 il int* Insert(RG int &x,RG int k){
 71     if (!x){ val[x=++tot]=k,sz[x]=cover[x]=1; return NULL; }
 72     sz[x]++,cover[x]++; int *p=Insert(ch[x][val[x]<=k],k);
 73     if (max(cover[ch[x][0]],cover[ch[x][1]])>cover[x]*alpha) p=&x;
 74     return p;
 75 }
 76 
 77 il void insert(RG int k){ int *x=Insert(rt,k); if (x) rebuild(*x); return; }
 78 
 79 il void Erase(RG int x,RG int k){
 80     while (x){
 81     sz[x]--; if (!del[x] && k==sz[ch[x][0]]+1){ del[x]=1; return; }
 82     if (k<=sz[ch[x][0]]) x=ch[x][0]; else k-=sz[ch[x][0]]+(!del[x]),x=ch[x][1];
 83     }
 84     return;
 85 }
 86 
 87 il void erase(RG int k){ Erase(rt,qrank(rt,k)); if (sz[rt]<cover[rt]*alpha) rebuild(rt); return; }
 88 
 89 il void work(){
 90     Q=gi(); RG int type,x;
 91     while (Q--){
 92     type=gi(),x=gi();
 93     if (type==1) insert(x);
 94     if (type==2) erase(x);
 95     if (type==3) printf("%d\n",qrank(rt,x));
 96     if (type==4) printf("%d\n",find(rt,x));
 97     if (type==5) printf("%d\n",find(rt,qrank(rt,x)-1));
 98     if (type==6) printf("%d\n",find(rt,qrank(rt,x+1)));
 99     }
100     return;
101 }
102 
103 int main(){
104     File("tree");
105     work();
106     return 0;
107 }