52分求调

#include<bits/stdc++.h>
#include<algorithm>
using namespace std;
#define int long long
const int INF=1e9;
int n,s,e,ans=INF;
int a[220],vis[220];
void dfs(int x,int s){
	if(x==e){
		ans=min(ans,s);
		return;
	}
	if(x+a[x]<=n&&vis[x+a[x]]==0){
		vis[x]=1;
		dfs(x+a[x],s+1);
		vis[x]=0;
	}
	if(x-a[x]>=1&&vis[x-a[x]]==0){
		vis[x]=1;
		dfs(x-a[x],s+1);
		vis[x]=0; 
	}
	return;
}
signed main(){
	int i;
	cin>>n>>s>>e;
	for(i=1;i<=n;i++){
		cin>>a[i];
	}
	dfs(s,0);
	if(ans==INF){
		cout<<-1;
	}
	else{
		cout<<ans;
	}
	return 0;
}