必须用广搜，深搜不行吗```c
#include<bits/stdc++.h>
using namespace std;
int n,x,y,a[205],sum=-1;
void dfs(int wz,int sl){
if(wz==y){sum=max(sum,sl);return;}if(sl>n)return;
if(wz-a[wz]>=1)dfs(wz-a[wz],sl+1);
if(wz+a[wz]<=n)dfs(wz+a[wz],sl+1);
}
int main(){
cin>>n>>x>>y;for(int i=1;i<=n;i++)cin>>a[i];
dfs(x,0);
if(sum>=0)cout<<sum;else cout<<-1;
return 0;
}
