思路：

LCT啊...

（分块也行）

不过YOUSIKI出了一道“弹飞大爷” 就不能用分块水过去了

//By SiriusRen#include 
     
      #include 
      
       using namespace std;const int N=200050;int fa[N],ch[N][2],rev[N],size[N],n,op,q[N],top,a[N],m,xx,yy;bool isroot(int x){
   return ch[fa[x]][0]!=x&&ch[fa[x]][1]!=x;}void push_up(int x){size[x]=size[ch[x][0]]+size[ch[x][1]]+1;}void push_down(int x){
   if(rev[x])rev[x]=0,rev[ch[x][0]]^=1,rev[ch[x][1]]^=1,swap(ch[x][0],ch[x][1]);}void rotate(int p){    int q=fa[p],y=fa[q],f=(ch[q][1]==p);    ch[q][f]=ch[p][!f],fa[ch[q][f]]=q;    ch[p][!f]=q,fa[p]=y;    if(!isroot(q)){        if(ch[y][0]==q)ch[y][0]=p;        if(ch[y][1]==q)ch[y][1]=p;    }fa[q]=p;push_up(q);}void splay(int x){    q[++top]=x;    for(int i=x;!isroot(i);i=fa[i])q[++top]=fa[i];    while(top)push_down(q[top--]);    for(int y=fa[x];!isroot(x);rotate(x),y=fa[x])if(!isroot(y)){        if((ch[y][0]==x)^(ch[fa[y]][0]==y))rotate(x);        else rotate(y);    }push_up(x);}void access(int x){
   for(int t=0;x;t=x,x=fa[x])splay(x),ch[x][1]=t,push_up(x);}void makeroot(int x){access(x),splay(x),rev[x]^=1;}void link(int x,int y){makeroot(x),fa[x]=y;}void cut(int x,int y){makeroot(x),access(y),splay(y);ch[y][0]=fa[x]=0;}void split(int x,int y){makeroot(x),access(y),splay(y);}int main(){    scanf("%d",&n);    for(int i=1;i<=n;i++)scanf("%d",&a[i]);    for(int i=1;i<=n;i++)link(i,a[i]+i>n?n+1:a[i]+i);    scanf("%d",&m);    while(m--){        scanf("%d%d",&op,&xx),xx++;        if(op==1)split(n+1,xx),printf("%d\n",size[xx]-1);        else scanf("%d",&yy),cut(xx,xx+a[xx]>n?n+1:xx+a[xx]),a[xx]=yy,link(xx,xx+a[xx]>n?n+1:xx+a[xx]);    }}