58分求调（玄关）

#include<bits/stdc++.h>
using namespace std;
int n,s,e;
int a[201];
bool dis[210];
struct node{
	int step;
	int l;
};
queue<node> q;
int main(){
	cin>>n>>s>>e;
	for(int i=1;i<=n;i++){
		scanf("%d",&a[i]);
	}
	if(s==e){
		cout<<0;
		return 0;
	}
	q.push({0,s});
	dis[s]=1;
	int ans=1e4;
	bool f=0;
	while(!q.empty()){
		node u=q.front();
		q.pop();
		if(u.l==e){
			ans=min(u.step,ans);
			f=1;
		}
		if(u.l+a[u.l]<=n&&dis[u.l+a[u.l]]==0){
			node v;
			v.l=u.l+a[u.l],v.step=u.step+1;
			q.push(v);
			dis[v.l]=1;
		}else if(u.l-a[u.l]>=0&&dis[u.l-a[u.l]]==0){
			node v;
			v.l=u.l-a[u.l],v.step=u.step+1;
			q.push(v);
			dis[v.l]=1;
		}else{
			continue;
		}
	}
	if(f)cout<<ans;
	else cout<<-1;
}
/*5 4 1
0 1 3 2 1*/