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[2]={2147483647,-2147483647};
int fa[100010],count[100010],son[100010][3],val[100010],data[100010];
int root,x,y,n,tot,xiugai;
void read(int &k)
{
    k=0;int f=1;char c=getchar();
    while(c<'0'||c>'9')c=='-'&&(f=-1),c=getchar();
    while(c<='9'&&c>='0')k=k*10+c-'0',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][0]]+count[son[f][1]]+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][0])return search(son[x][0],y);
    if(data[x]<y&&son[x][1])return search(son[x][1],y);
    return x;
}
int ext(int x,int w)
{
    int k=search(x,extar[w]);
    splay(k,0);
    return data[k];
}
int pred(int w)
{
    int k=search(root,w);
    splay(k,0);
    if(data[k]<w)return data[k];
    return ext(son[k][0],0);
}
int succ(int x)
{
    int k=search(root,x);
    splay(k,0);
    if(data[k]>x)return data[k];
    return ext(son[k][1],1);
}
int rank(int x,int k)
{
    if(k<=count[son[x][0]])return rank(son[x][0],k);
    if(k<=(count[son[x][0]]+val[x]))return x;
    return rank(son[x][1],k-count[son[x][0]]-val[x]);
}
int findnum(int x)
{
    int k=search(root,x);
    splay(k,0);
    return count[son[k][0]]+1;
}
void insert(int &x,int w,int f)
{
    if(!x)
    {
        x=++tot;
        count[x]=val[x]=1;
        data[x]=w;
        fa[x]=f;
        xiugai=tot;
        return;
    }
    if(data[x]==w)val[x]++,xiugai=x;
    if(data[x]<w)insert(son[x][1],w,x);
    if(data[x]>w)insert(son[x][0],w,x);
    count[x]++;
}
void del(int w)
{
    int k=search(root,w);
    splay(k,0);
    if(data[k]==w)
    {
        if(val[k]>1)val[k]--,count[k]--;
        else
        if(!son[k][0])
        {
            root=son[k][1];
            fa[root]=fa[k]=son[k][1]=count[k]=val[k]=data[k]=0;
        }
        else
        {
            fa[son[k][0]]=0;ext(son[k][0],0);
            son[root][1]=son[k][1];
            if(son[k][1])fa[son[k][1]]=root;
            count[root]+=count[son[k][1]];
            fa[k]=son[k][0]=son[k][1]=data[k]=val[k]=count[k]=0;
        }
    }
}
int main()
{
    read(n);
    for(int i=1;i<=n;i++)
    {
        read(x);read(y);
        switch(x)
        {
            case 1:insert(root,y,0);splay(xiugai,0);root=xiugai;break;
            case 2:del(y);break;
            case 3:printf("%d
",findnum(y));break;
            case 4:printf("%d
",data[rank(root,y)]);break;
            case 5:printf("%d
",pred(y));break;
            case 6:printf("%d
",succ(y));break;
            default:break;
        }
    }
}