Splay，TLE，only AC on #3、#14

#include<bits/stdc++.h>
using namespace std;
int n,op,x,rt,siz,fa[100010],son[100010][10],num[100010],cnt[100010],sz[100010];
void all_zero(int x){
	fa[x]=0;
	son[x][0]=0;
	son[x][1]=0;
	num[x]=0;
	cnt[x]=0;
	sz[x]=0;
}int get(int x){
	if(x==son[fa[x]][0]){
		return 0;
	}return 1;
}void pushup(int x){
	if(x>=1){
		sz[x]=cnt[x];
		if(son[x][0]>=1){
			sz[x]+=sz[son[x][0]];
		}if(son[x][1]>=1){
			sz[x]+=sz[son[x][1]];
		}
	}
}void rotate(int x){
	int f=fa[x],flag=get(x);
	int gra=fa[f];
	son[f][flag]=son[x][flag^1];
	fa[son[f][flag]]=f;
	son[x][flag^1]=f;
	fa[f]=x,fa[x]=gra;
	if(gra>=1){
		if(son[gra][1]==f){
			son[gra][1]=x;
		}else{
			son[gra][0]=x;
		}
	}pushup(f),pushup(x);
}void Splay(int x){
	for(int f;f=fa[x];rotate(x)){
		if(fa[f]>=1){
			if(get(x)==get(f)){
				rotate(f);
			}else{
				rotate(x);
			}
		}
	}rt=x;
}void insert(int x){
	if(rt==0){
		siz++,rt=siz;
		son[rt][0]=son[rt][1]=fa[rt]=0;
		num[rt]=x,cnt[rt]=1,sz[rt]=1;
		return;
	}int now=rt,f=0;
	while(1){
		if(num[now]==x){
			cnt[now]++;
			pushup(now),pushup(f);
			Splay(now);
			return;
		}f=now;
		if(x>num[now]){
			now=son[now][1];
		}else{
			now=son[now][0];
		}if(now==0){
			siz++;
			son[siz][0]=son[siz][1]=0;
			num[siz]=x;
			cnt[siz]=1,sz[siz]=1;
			fa[siz]=f;
			if(x>num[now]){
				son[f][1]=siz;
			}else{
				son[f][0]=siz;
			}pushup(f);
			Splay(siz);
			return;
		}
	}
}int find_key(int x){
	int ret=0,now=rt;
	while(1){
		if(x<num[now]){
			now=son[now][0];
		}else{
			if(son[now][0]>=1){
				ret+=sz[son[now][0]];
			}if(x==num[now]){
				Splay(now);
				return ret+1;
			}ret+=cnt[now];
			now=son[now][1];
		}
	}
}int find_th(int x){
	int now=rt;
	while(1){
		if(son[now][0]>=1&&x<=sz[son[now][0]]){
			now=son[now][0];
		}else{
			int tmp=cnt[now];
			if(son[now][0]>=1){
				tmp+=sz[son[now][0]];
			}if(now<=tmp){
				return num[now];
			}x-=tmp;
			now=son[now][1];
		}
	}
}int pre(){
	int now=son[rt][0];
	while(son[now][1]>=1){
		now=son[now][1];
	}return now;
}int nxt(){
	int now=son[rt][1];
	while(son[now][0]>=1){
		now=son[now][0];
	}return now;
}void del(int x){
	find_key(x);
	if(cnt[rt]>1){
		cnt[rt]--;
		pushup(rt);
		return;
	}else if(son[rt][0]==son[rt][1]==0){
		all_zero(rt);
		rt=0,siz=0;
		return;
	}else if(son[rt][0]==0){
		int tmp=rt;
		rt=son[rt][1];
		fa[rt]=0;
		all_zero(tmp);
		siz--;
		return;
	}else if(son[rt][1]==0){
		int tmp=rt;
		rt=son[rt][0];
		fa[rt]=0;
		all_zero(tmp);
		siz--;
		return;
	}int rt_pre=pre(),tmp=rt;
	Splay(rt_pre);
	fa[son[tmp][1]]=rt,son[rt][1]=son[tmp][1];
	all_zero(tmp);
	pushup(rt);
	return;
}int main(){
	scanf("%d",&n);
	while(n--){
		scanf("%d%d",&op,&x);
		if(op==1){  
			insert(x);
		}else if(op==2){
			del(x);
		}else if(op==3){
			printf("%d\n",find_key(x));
		}else if(op==4){
			printf("%d\n",find_th(x));
		}else if(op==5){
			insert(x);
			printf("%d\n",num[pre()]);
			del(x);
		}else if(op==6){
			insert(x);
			printf("%d\n",num[nxt()]);
			del(x);
		}
	}return 0;
}//Splay and play S \cf