splay模板

1.updata

void updata(int x)
{
    count2[x]=count2[leftson[x]]+count2[rightson[x]]+1;（加上自己信息）
}

2.rotate

void rotate(int x,int y)
{
    int father=fa[x];
    if (y==1)
    {
        rightson[father]=leftson[x];
        if (leftson[x]) fa[leftson[x]]=father;
    } else
    {
        leftson[father]=rightson[x];
        if (rightson[x]) fa[rightson[x]]=father;
    }
    fa[x]=fa[father];
    if (fa[father])
    {
        if (leftson[fa[father]]==father) leftson[fa[father]]=x;
        else rightson[fa[father]]=x;
    }
    fa[father]=x;
    if (y==1) leftson[x]=father;else rightson[x]=father;
    updata(father); updata(x);
}

3.splay

void splay(int x,int goal)
{
    if (x==root) return;
    int father=fa[x];
    while (father!=goal)
    {
        if (fa[father]==goal)
        {
            if (x==leftson[father]) rotate(x,2); else rotate(x,1);
        } else
        {
            if (father==leftson[fa[father]])
            {
                if (x==leftson[father]) rotate(father,2),rotate(x,2);
                else rotate(x,1),rotate(x,2);
            } else
            {
                if (x==rightson[father]) rotate(father,1),rotate(x,1);
                else rotate(x,2),rotate(x,1);
            }
        }
        father=fa[x];
    }
    if (goal==0) root=x;
} 

4.search

int search(int goal)
{
    int x=root,cnt=1;
    while (x)
    {
        if (cnt+count2[leftson[x]]==goal) return(x);
        if (count2[leftson[x]]+cnt<goal)
        {
            cnt+=count2[leftson[x]]+1; x=rightson[x];
        } else
        {
            x=leftson[x];
        }
    }
}

5.build

#define mid (h+t)/2 
void build(int h,int t,int father,bool x,int a[maxn])
{
  count2[++num]=1; data[num]=a[mid]; fa[num]=father;if (father)
  {
      if (x==1) leftson[father]=num; else rightson[father]=num;
    }
    int tmp=num;
    if (h<mid) build(h,mid-1,tmp,1,a);
    if (mid<t) build(mid+1,t,tmp,0,a);
    updata(tmp);
}
root=(1+n)/2;

6.insert

void insert2(int x)
{
    int y=root;
    while (y)
    {
        count2[y]++;
        if (x<data[y])
        {
            if (!leftson[y]) break;
            y=leftson[y];
        } else
        {
            if (!rightson[y]) break;
            y=rightson[y];
        }
    }
    data[++num]=x; fa[num]=y; count2[num]=1;
    if (x>=data[y]) rightson[y]=num; //注意这个等号 由于上面是小于 所以一定要有
    else leftson[y]=num; 
    splay(num,0);
}

7.pre

 int y=root,maxn=-INF;
  while (y)
  {
      if (data[y]<=x) maxn=max(maxn,data[y]);
      if (data[y]<=x) y=rightson[y];
      else y=leftson[y];
    }

8. print

void print(int x)
{
    down(x);
    if (leftson[x]!=0) print(leftson[x]);
    if(data[x]>=1&&data[x]<=n) cout<<data[x]<<" ";
    if (rightson[x]!=0) print(rightson[x]);
}

 9.delete2

void delete1()
{
    int x=leftson[root];
    if (x==0)
    {
        root=rightson[root]; fa[root]=0; return;
    }
    while (rightson[x]) x=rightson[x];
    splay(x,root); 
    rightson[x]=rightson[root];
    if (rightson[root]) fa[rightson[root]]=x;
    updata(x);
    root=x; fa[x]=0;
}

 10.query