- 1 #include<iostream>
- 2 #include<cmath>
- 3 #include<cstring>
- 4 #include<algorithm>
- 5 #include<cstdio>
- 6 #define db double
- 7 using namespace std;
- 8 const int N=200005;
- 9 int n,m,a[N],t1,t2,t3,siz,s,t,to[N],stp[N];
- 10 int query(int p){
- 11 int rt=0;while(~p){
- 12 rt+=stp[p];p=to[p];
- 13 } return rt;
- 14 } void update(int p,int da){
- 15 s=p/siz*siz;t=(p/siz+1)*siz-1;
- 16 a[p]=da;for(int i=p;i>=s;i--)
- 17 if(i+a[i]>=n) to[i]=-1,stp[i]=1;
- 18 else if(i+a[i]>t) to[i]=i+a[i],stp[i]=1;
- 19 else to[i]=to[i+a[i]],stp[i]=stp[i+a[i]]+1;
- 20 } int main(){
- 21 scanf("%d",&n);siz=(int)sqrt((db)n+0.5);
- 22 for(int i=0;i<n;i++) scanf("%d",&a[i]);
- 23 for(int i=n-1;~i;i--){
- 24 t=(i/siz+1)*siz-1;
- 25 if(i+a[i]>=n) to[i]=-1,stp[i]=1;
- 26 else if(i+a[i]>t)
- 27 to[i]=i+a[i],stp[i]=1;
- 28 else to[i]=to[i+a[i]],
- 29 stp[i]=stp[i+a[i]]+1;
- 30 } scanf("%d",&m);
- 31 while(m--){
- 32 scanf("%d%d",&t1,&t2);
- 33 if(t1==1) printf("%d\n",query(t2));
- 34 else scanf("%d",&t3),update(t2,t3);
- 35 } return 0;
- 36 }