bzoj3224: Tyvj 1728 普通平衡树(打个splay暖暖手)

　　（其实今天好热啊？

　　题目大意：插入，删除，k小，前驱后继，数的排名。

　　splay和treap裸题...过几天补个treap的

splay:

#include<iostream>
#include<cstdlib>
#include<cstring>
#include<cstdio>
#define which(x) (son[fa[x]][1]==x)
using namespace std;
const int extar[]={,-};
int fa[],count[],son[][],val[],data[];
int root,x,y,n,tot,xiugai;
void read(int &k)
{
    k=;int f=;char c=getchar();
    while(c<''||c>'')c=='-'&&(f=-),c=getchar();
    while(c<=''&&c>='')k=k*+c-'',c=getchar();
    k*=f;
}
void rotate(int x)
{
    int f=fa[x];
    bool k=which(x);
    son[f][k]=son[x][!k];son[x][!k]=f;son[fa[f]][which(f)]=x;
    if(son[f][k])fa[son[f][k]]=f;fa[x]=fa[f];fa[f]=x;
    count[x]=count[f];
    count[f]=count[son[f][]]+count[son[f][]]+val[f];
}
void splay(int x,int g)
{
    while(fa[x]!=g)
    {
        int f=fa[x];
        if(fa[f]==g)
        {
            rotate(x);
            break;
        }
        if(which(x)^which(f))rotate(x);
        else rotate(f);
        rotate(x);
    }
    if(!g)root=x;
}
int search(int x,int y)
{
    if(data[x]>y&&son[x][])return search(son[x][],y);
    if(data[x]<y&&son[x][])return search(son[x][],y);
    return x;
}
int ext(int x,int w)
{
    int k=search(x,extar[w]);
    splay(k,);
    return data[k];
}
int pred(int w)
{
    int k=search(root,w);
    splay(k,);
    if(data[k]<w)return data[k];
    return ext(son[k][],);
}
int succ(int x)
{
    int k=search(root,x);
    splay(k,);
    if(data[k]>x)return data[k];
    return ext(son[k][],);
}
int rank(int x,int k)
{
    if(k<=count[son[x][]])return rank(son[x][],k);
    if(k<=(count[son[x][]]+val[x]))return x;
    return rank(son[x][],k-count[son[x][]]-val[x]);
}
int findnum(int x)
{
    int k=search(root,x);
    splay(k,);
    return count[son[k][]]+;
}
void insert(int &x,int w,int f)
{
    if(!x)
    {
        x=++tot;
        count[x]=val[x]=;
        data[x]=w;
        fa[x]=f;
        xiugai=tot;
        return;
    }
    if(data[x]==w)val[x]++,xiugai=x;
    if(data[x]<w)insert(son[x][],w,x);
    if(data[x]>w)insert(son[x][],w,x);
    count[x]++;
}
void del(int w)
{
    int k=search(root,w);
    splay(k,);
    if(data[k]==w)
    {
        if(val[k]>)val[k]--,count[k]--;
        else
        if(!son[k][])
        {
            root=son[k][];
            fa[root]=fa[k]=son[k][]=count[k]=val[k]=data[k]=;
        }
        else
        {
            fa[son[k][]]=;ext(son[k][],);
            son[root][]=son[k][];
            if(son[k][])fa[son[k][]]=root;
            count[root]+=count[son[k][]];
            fa[k]=son[k][]=son[k][]=data[k]=val[k]=count[k]=;
        }
    }
}
int main()
{
    read(n);
    for(int i=;i<=n;i++)
    {
        read(x);read(y);
        switch(x)
        {
            case :insert(root,y,);splay(xiugai,);root=xiugai;break;
            case :del(y);break;
            case :printf("%d\n",findnum(y));break;
            case :printf("%d\n",data[rank(root,y)]);break;
            case :printf("%d\n",pred(y));break;
            case :printf("%d\n",succ(y));break;
            default:break;
        }
    }
}