bzoj1861 书架

bzoj1861 书架

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原题链接

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神题。。。

先吐槽洛谷的样例

10 10
1 3 2 7 5 8 10 4 9 6
Query 3
Top 5
Ask 6
Bottom 3
Ask 3
Top 6
Insert 4 –1
Query 5
Query 2
Ask 2

bzoj的样例

10 10
1 3 2 7 5 8 10 4 9 6
Query 3
Top 5
Ask 6
Bottom 3
Ask 3
Top 6
Insert 4 -1
Query 5
Query 2
Ask 2

区别？–号与-号。。。

于是洛谷样例被我改了！！！

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吐槽完毕

如果你知道书在哪这就是treap裸题。

然而不知道

所以，要知道书在哪。

可以一开始记录一下每个点的地址。

地址永远不会改变对吧

然后？一直跳father，如果他是father的rs就ans+=father的ls的size+1

ans初值为ls的size+1

为什么是对的？自己想

然而treap并不能维护father，只好加一个

updata时顺便更新

il vd reset(){
    size=ls->size+rs->size+1;
    if(ls!=null)ls->fa=this;if(rs!=null)rs->fa=this;
}

然后？treap裸题a

1A了

// It is made by XZZ
#include<cstdio>
#include<algorithm>
using namespace std;
#define rep(a,b,c) for(rg int a=b;a<=c;a++)
#define drep(a,b,c) for(rg int a=b;a>=c;a--)
#define erep(a,b) for(rg int a=fir[b];a;a=nxt[a])
#define il inline
#define rg register
#define vd void
#define mp make_pair
#define pr pair<point,point>
#define fir first
#define sec second
typedef long long ll;
il int gi(){
    rg int x=0;rg char ch=getchar();
    while(ch<'0'||ch>'9')ch=getchar();
    while(ch>='0'&&ch<='9')x=x*10+ch-'0',ch=getchar();
    return x;
}
const int maxn=80010;
int A[maxn],n;
int seed=233333;
il int Rand(){return seed=seed*23333ll%19260817;}
typedef struct node* point;
point null;
struct node{
    int num,size,rand;
    point ls,rs,fa;
    node(int _num){num=_num,size=1,rand=Rand(),ls=rs=fa=null;}
    il vd reset(){
    size=ls->size+rs->size+1;
    if(ls!=null)ls->fa=this;if(rs!=null)rs->fa=this;
    }
};point root,pos[maxn];
il point build(int n){
    point stk[n+1],now,lst;int top=0;
    rep(i,1,n){
    pos[A[i]]=now=new node(A[i]),lst=null;
    while(top&&stk[top]->rand>now->rand)lst=stk[top],stk[top--]->reset();
    if(top)stk[top]->rs=now;now->ls=lst,stk[++top]=now;
    }
    while(top)stk[top--]->reset();
    return stk[1];
}
il point merge(point a,point b){
    if(a==null)return b;
    if(b==null)return a;
    if(a->rand<b->rand){a->rs=merge(a->rs,b),a->reset();return a;}
    b->ls=merge(a,b->ls),b->reset();return b;
}
il pr split(point x,int num){
    if(x==null)return mp(null,null);
    point ls=x->ls,rs=x->rs;
    if(num==x->ls->size){x->ls=null,x->reset();return mp(ls,x);}
    if(num==x->ls->size+1){x->rs=null,x->reset();return mp(x,rs);}
    if(num<x->ls->size){pr t=split(x->ls,num);x->ls=t.sec;x->reset();return mp(t.fir,x);}
    pr t=split(x->rs,num-x->ls->size-1);x->rs=t.fir;x->reset();return mp(x,t.sec);
}
il int getpos(point x){
    int ret=x->ls->size+1;
    while(x->fa!=null){
    if(x==x->fa->rs)ret+=x->fa->ls->size+1;
    x=x->fa;
    }return ret;
}
int main(){
    n=gi();
    int m=gi();
    null=new node(0);
    null->size=0,null->ls=null->rs=null->fa=null;
    rep(i,1,n)A[i]=gi();
    root=build(n);
    int S,T,p;
    pr t1,t2,t3;point x;
    char opt;
    while(m--){
    do opt=getchar();while(opt<'A'||opt>'Z');
    if(opt=='T'){
        S=gi(),p=getpos(pos[S]);
        t1=split(root,p-1),t2=split(t1.sec,1);
        root=merge(t2.fir,merge(t1.fir,t2.sec));
    }
    else if(opt=='B'){
        S=gi(),p=getpos(pos[S]);
        t1=split(root,p-1),t2=split(t1.sec,1);
        root=merge(merge(t1.fir,t2.sec),t2.fir);
    }
    else if(opt=='I'){
        S=gi(),scanf("%d",&T),p=getpos(pos[S]);
        if(T==0)continue;
        if(T==1)t1=split(root,p-1);else t1=split(root,p-2);
        t2=split(t1.sec,1),t3=split(t2.sec,1);
        root=merge(merge(merge(t1.fir,t3.fir),t2.fir),t3.sec);
    }
    else if(opt=='A')S=gi(),printf("%d\n",getpos(pos[S])-1);
    else if(opt=='Q'){
        p=gi();
        t1=split(root,p-1);
        x=t1.sec;while(x->ls!=null)x=x->ls;
        printf("%d\n",x->num);
        root=merge(t1.fir,t1.sec);
    }
    }
    return 0;
}