弹飞绵羊

链接：https://www.luogu.org/problemnew/show/P3203

题解：

lct模板题

代码：

 

#include <bits/stdc++.h>
using namespace std;
#define maxn 300000
int n,m,num,root,fa[maxn],leftson[maxn],rightson[maxn];
int count2[maxn],v[maxn];
bool rev[maxn];
void down(int x)
{
  if (!rev[x]) return;
  swap(leftson[x],rightson[x]); rev[x]=0;
  rev[leftson[x]]^=1; rev[rightson[x]]^=1; 
}
void updata(int x)
{
    down(x);
    count2[x]=count2[leftson[x]]+count2[rightson[x]]+1;
}
void pushr(int x)
{
  rev[x]^=1;
}
bool pd(int x)
{
  int y=fa[x];
  if (leftson[y]!=x&&rightson[y]!=x) return(false);
  else return(true);
}
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 (pd(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);
}
void dfs(int x)
{
  if (pd(x)) dfs(fa[x]);
  down(x);
}
void splay(int x)
{
  dfs(x);
  int father=fa[x];
  while (pd(x))
  {
    if (!pd(father))
    {
      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];
  }
}
void access(int x)
{
  for (int y=0;x;y=x,x=fa[x])
    splay(x),rightson[x]=y,updata(x);
}
void makeroot(int x)
{
  access(x);
  splay(x);
  pushr(x);
}
int findroot(int x)
{
  access(x);
  splay(x);
  while (leftson[x]) x=leftson[x];
  return x;
}
void split(int x,int y)
{
  makeroot(x);
  access(y);
  splay(y);
}
void link(int x,int y)
{
  makeroot(x);
  if (findroot(y)!=x) fa[x]=y;
}
void cut(int x,int y)
{
  makeroot(x);
  if (findroot(y)==x&&fa[x]==y)
  {
    fa[x]=leftson[y]=0;
    updata(y);
  }
}
int main()
{
  freopen("noip.in","r",stdin);
  freopen("noip.out","w",stdout);
  cin>>n;
  int x,y;
  for (int i=0;i<=n-1;i++)
  {
    cin>>x;
    if (x+i<n) link(i+1,x+i+1),v[i]=x+i;
    else link(i+1,n+1),v[i]=n;
  }
  cin>>m; int c;
  while (m--)
  {
    cin>>c;
    if (c==1)
    {
      cin>>x;
      split(x+1,n+1); 
      cout<<count2[n+1]-1<<endl;
    }
    if (c==2)
    {
      cin>>x>>y;
      cut(x+1,v[x]+1);
      if (x+y<n) link(x+1,x+y+1),v[x]=x+y;
      else link(x+1,n+1),v[x]=n;
    }
  }
  return 0;
}