splay

 随便敲敲练手。。。

#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
const int inf=1e9;
const int maxn=200000;
int N,M,T,tot,root;
int key[maxn],lc[maxn],rc[maxn],fa[maxn],siz[maxn];
inline void update(int x){
siz[x]=siz[lc[x]]+siz[rc[x]]+1;
}
inline void r_rotate(int x){
int y=fa[x];
lc[y]=rc[x];
if(rc[x]) fa[rc[x]]=y;
fa[x]=fa[y];
if(y==lc[fa[y]]) lc[fa[y]]=x;
else rc[fa[y]]=x;
fa[y]=x; rc[x]=y;
update(y); update(x);
}
inline void l_rotate(int x){
int y=fa[x];
rc[y]=lc[x];
if(lc[x]) fa[lc[x]]=y;
fa[x]=fa[y];
if(y==lc[fa[y]]) lc[fa[y]]=x;
else rc[fa[y]]=x;
fa[y]=x; lc[x]=y;
update(y); update(x);
}
inline void splay(int x,int s){
int p;
while(fa[x]!=s){
int p=fa[x];
if(fa
==s){
if(x==lc[p]) r_rotate(x);
else l_rotate(x);
break;
}
else if(x==lc[p]){
if(p==lc[fa[p]]) r_rotate(x),r_rotate(x);
else r_rotate(x),l_rotate(x);
}
else if(x==rc[p]){
if(p==rc[fa[p]]) l_rotate(x),l_rotate(x);
else l_rotate(x),r_rotate(x);
}
}
if(s==0) root=x;
}

inline void insert(int v){
if(root==0){
root=++tot;
rc[0]=tot; key[root]=v; siz[root]=1;
return ;
}
int tmp,x=root;
while(x!=0){
tmp=x;
if(v<=key[x]) siz[x]++,x=lc[x];
else siz[x]++,x=rc[x];
}
if(v<=key[tmp]){
lc[tmp]=++tot;
fa[tot]=tmp; key[tot]=v; siz[tot]=1;
}
else{
rc[tmp]=++tot;
fa[tot]=tmp; key[tot]=v; siz[tot]=1;
}
splay(tot,0);
}

inline int find(int v){
int x=root;
while(x!=0){
if(v<key[x]) x=lc[x];
else if(v>key[x]) x=rc[x];
else{
splay(x,0);
return x;
}
}
return -1;
}

inline int getmax(int x){
int tmp;
while(x!=0){
tmp=x; x=rc[x];
}
return tmp;
}
inline int getmin(int x){
int tmp;
while(x!=0){
tmp=x; x=lc[x];
}
return tmp;
}

inline void Delete(int v){
int x=find(v);
if(x==-1) return ;
int pp=getmax(lc[x]),nn=getmin(rc[x]);
if(lc[x]==0||rc[x]==0){
if(lc[x]==0&&rc[x]==0){
root=0; rc[0]=0;
return ;
}
else if(lc[x]==0){
rc[0]=rc[x]; fa[rc[x]]=0; root=rc[x]; rc[x]=0;
siz[x]=1;
return ;
}
else{
rc[0]=lc[x]; fa[lc[x]]=0; root=lc[x]; lc[x]=0;
siz[x]=1;
return ;
}
}
splay(pp,0); splay(nn,root);
fa[lc[nn]]=0; siz[lc[nn]]=1; lc[nn]=0;
update(nn); update(pp);
}

inline int rank(int x,int v){
if(x==0) return 1;
if(v<=key[x]) return rank(lc[x],v);
else return siz[lc[x]]+1+rank(rc[x],v);
}
inline int findkth(int x,int k){
if(siz[lc[x]]+1==k) return key[x];
if(siz[lc[x]]+1>k) return findkth(lc[x],k);
return findkth(rc[x],k-siz[lc[x]]-1);
}
inline int pred(int rt,int v){
if(rt==0)  return v;
if(v<=key[rt]) return pred(lc[rt],v);
else{
int ans=pred(rc[rt],v);
if(ans==v) return key[rt];
return ans;
}
}
inline int succ(int rt,int v){
if(rt==0) return v;
if(v>=key[rt]) return succ(rc[rt],v);
else{
int ans=succ(lc[rt],v);
if(ans==v) return key[rt];
return ans;
}
}

int main(){
freopen("3224.in","r",stdin);
freopen("3224.out","w",stdout);
scanf("%d",&T);
while (T--){
int kin,num;
scanf("%d%d",&kin,&num);
if(kin==1) insert(num);
else if(kin==2) Delete(num);
else if(kin==3) printf("%d\n",rank(root,num));
else if(kin==4) printf("%d\n",findkth(root,num));
else if(kin==5) printf("%d\n",pred(root,num));
else if(kin==6) printf("%d\n",succ(root,num));
}
return 0;
}