splay半成品

#include<cstdio>
#include<algorithm>
#include<iostream>
using namespace std;
int inf=0x7fffffff;
struct node
{
    int num;
    int val;
    int size;
    node* ch[2];
    node (int v) :val(v)
    {
        size=1;
        num=1;
        ch[0]=ch[1]=NULL;
    }
    void sum()
    {
        size=num;
        if(ch[0]!=NULL)
            size+=ch[0]->size;
        if(ch[1]!=NULL)
            size+=ch[1]->size;
        return ;
    }
    int cmp(int v)
    {
        if(val==v)
            return -1;
        return (val>v ? 0 : 1);
    }
    int cmpkth(int k)
    {
        int s=( ch[0]==NULL ? 0 : ch[0]->size );
        if(k>s&&k<=s+num)
            return 1;
        if(k<=s)
            return 0;
        else
            return 1;
    }
};
node* root;
void rotato(node* &x,int base)
{
    node* k=x->ch[base^1];
    x->ch[base^1]=k->ch[base];
    k->ch[base]=x;
    x->sum();
    k->sum();
    x=k;
}
void splay(node* &x,int v)
{
    int d=x->cmp(v);
    if(d!=-1&&x->ch[d]!=NULL)
    {
        int d2=x->ch[d]->cmp(v);
        if(d2!=-1&&x->ch[d]->ch[d2]!=NULL)
        {
            splay(x->ch[d]->ch[d2],v);
            if(d==d2)
                rotato(x,d2^1),rotato(x,d^1);
            else
                rotato(x->ch[d],d2^1),rotato(x,d^1);
        }
        else
            rotato(x,d^1);
    }
}
void splaykth(node *x,int k)
{
    int d=x->cmpkth(k);
    if(d!=-1)
    {
        if(d==1)
            k-=x->ch[0]->size-x->num;
        int d2=x->ch[d]->cmpkth(k);
        if(d2!=-1)
        {
            int k2=(d2==1 ? k-x->ch[d]->ch[0]->size-x->ch[d]->num : k);
            splaykth(x->ch[d]->ch[d2],k2);
            if(d==d2)
                rotato(x,d2^1),rotato(x,d^1);
            else
                rotato(x->ch[d],d2^1),rotato(x,d^1);
        }
        else
            rotato(x,d^1);
    }
    return ;
}
void pre(node* x,int val,int &ans)
{
    if(x==NULL)
        return ;
    if(x->val<val)
    {
        if(x->val>ans)
            ans=x->val;
        if(x->ch[1]!=NULL)
            pre(x->ch[1],val,ans);
    }
    else
        if(x->val>val&&x->ch[0]!=NULL)
            pre(x->ch[0],val,ans);
}
void nxt(node* x,int val,int ans)
{
    if(x==NULL)
        return ;
    if(x->val>val)
    {
        if(x->val<ans)
            ans=x->val;
        if(x->ch[0]!=NULL)
            pre(x->ch[0],val,ans);
    }
    else
        if(x->val<val&&x->ch[1]!=NULL)
            pre(x->ch[1],val,ans);
}
int find(node* x,int val)
{
    splay(x,val);
    return x->ch[0]->size;
}
int kth(node* x,int k)
{
    splaykth(x,k);
    return x->val;
}
node *spilt(node* &x,int val)
{
    if(x==NULL)
        return NULL;
    splay(x,val);
    node* t1;
    node* t2;
    if(x->val<=val)
        t1=x,t2=x->ch[1],t1->ch[1]=NULL;
    else
        t2=x,t1=x->ch[0],t2->ch[0]=NULL;
    x->sum();
    x=t1;
    return t2;
}
void merge(node* &t1,node* &t2)
{
    if(t1==NULL)
        swap(t1,t2);
    splay(t1,inf);
    t1->ch[1]=t2;
    t2=NULL;
    t1->sum();
}
void insert(node* &x,int val)
{
    node* t2=spilt(x,val);
    if(x->val==val)
    {
        x->num+=1;
        x->sum();
    }
    else
    {
        node* nw=new node(val);
        merge(x,nw);
    }
    merge(x,t2);
}
void erase(node* &x,int val)
{
    node* t2=spilt(x,val);
    t2->num-=1;
    if(t2->num==0)
        x=x->ch[0];
    merge(x,t2);
}
int main()
{
    return 0;
}