BZOJ 1861 书架

（╯－＿－）╯╧╧

此处为错误代码。

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#define maxn 300050
#define inf 2147483646
using namespace std;
int n,m,a[maxn],x,y;
int tree[maxn][],size[maxn],fath[maxn],val[maxn],root,hash[maxn],rr=;
char s[];
void pushup(int now)
{
    size[now]=size[tree[now][]]+size[tree[now][]]+;
}
void reset(int x)
{
    fath[x]=tree[x][]=tree[x][]=;
    size[x]=;
}
void sets(int x,int y)
{
    swap(fath[x],fath[y]);
    if (fath[x]==y)
    {
        fath[x]=fath[y];fath[y]=x;

    }
}
void build(int &now,int left,int right,int father)
{
    if (left>right) return;
    int mid=(left+right)>>;now=mid;
    fath[now]=father;val[now]=a[mid];
    build(tree[now][],left,mid-,now);
    build(tree[now][],mid+,right,now);
    pushup(now);
}
void rotate(int x,int &k)
{
    int y=fath[x],z=fath[y],l,r;
    if (tree[y][]==x) l=;else l=;
    r=-l;
    if (y==k) k=x;
    else
    {
        if (tree[z][]==y) tree[z][]=x;
        else tree[z][]=x;
    }
    fath[x]=z;fath[y]=x;fath[tree[x][r]]=y;
    tree[y][l]=tree[x][r];tree[x][r]=y;
    pushup(y);pushup(x);
}
void splay(int x,int &k)
{
    while (x!=k)
    {
        int y=fath[x],z=fath[y];
        if (y!=k)
        {
            if ((tree[y][]==x)^(tree[z][]==y)) rotate(x,k);
            else rotate(y,k);
        }
        rotate(x,k);
    }
}
int get_pre(int x)
{
    int ret=tree[x][];
    while (tree[ret][])
        ret=tree[ret][];
    return ret;
}
int get_sub(int x)
{
    int ret=tree[x][];
    while (tree[ret][])
        ret=tree[ret][];
    return ret;
}
void delete_(int x)
{
    splay(x,root);
    int pre=get_pre(root);
    int ls=tree[x][],rs=tree[x][];
    root=ls;fath[ls]=fath[rs]=;splay(pre,root);
    tree[root][]=rs;fath[rs]=root;pushup(root);
    reset(x);
}
int find_kth(int now,int x)
{
    int r=size[tree[now][]];
    if (x<=r) return find_kth(tree[now][],x);
    else if (x>r+) return find_kth(tree[now][],x-r-);
    else
    {
        rr=now;
        return now;
    }
}
int get_rank(int x)
{
    splay(x,root);
    return size[tree[root][]];
}
int main()
{
    scanf("%d%d",&n,&m);
    for (int i=;i<=n;i++)
    {
        scanf("%d",&a[i+]);
        hash[a[i+]]=i+;
    }
    a[]=n+;a[n+]=n+;
    build(root,,n+,);
    for (int i=;i<=m;i++)
    {
        scanf("%s",s);
        if (s[]=='T')
        {
            scanf("%d",&x);
            delete_(hash[x]);
            y=find_kth(root,);
            splay(y,root);
            int rs=tree[root][];
            reset(root);
            fath[root]=hash[x];fath[rs]=hash[x];tree[hash[x]][]=root;tree[hash[x]][]=rs;pushup(hash[x]);
            root=hash[x];
            splay((n+)>>,root);
        }
        else if (s[]=='B')
        {
            scanf("%d",&x);
            delete_(hash[x]);
            y=find_kth(root,n+);
            splay(y,root);
            int ls=tree[root][];
            reset(root);
            fath[root]=hash[x];fath[ls]=hash[x];tree[hash[x]][]=root;tree[hash[x]][]=ls;pushup(hash[x]);
            root=hash[x];
            splay((n+)>>,root);
        }
        else if (s[]=='I')
        {
            scanf("%d%d",&x,&y);
            if (y==) continue;
            else if (y==-)
            {
                int pre=get_pre(hash[x]);
                sets(pre,hash[x]);
            }
            else
            {
                int sub=get_sub(hash[x]);
                sets(hash[x],sub);
            }
            splay(hash[x],root);
        }
        else if (s[]=='A')
        {
            scanf("%d",&x);
            printf("%d\n",get_rank(hash[x])-);
            splay(hash[x],root);
    }
        else
        {
            rr=;
            scanf("%d",&x);
            printf("%d\n",val[find_kth(root,x+)]);
            splay(rr,root);
        }
    }
    return ;
}