样例通过，64pts，检查不出错来

上代码

#include <bits/stdc++.h>
#include <queue>
using namespace std;
bool vis[202];
int n,nw,to,k[202];
struct pos{
	int x,step;
	pos(int px=0,int py=0){
		x=px;
		step=py;
	}
};
void bfs(){
	queue<pos> q;
	q.push(pos(1,0));
	while(!q.empty()){
		pos now=q.front();
		if(now.x==to){
			cout<<now.step;
			return;
		}
		q.pop();
		int x=now.x,step=now.step;
		if(x+k[x]<=n&&vis[x+k[x]]==0){
			q.push(pos(x+k[x],step+1));
			vis[x+k[x]]=1;
		}
		if(x-k[x]>=1&&vis[x-k[x]]==0){
			q.push(pos(x-k[x],step+1));
			vis[x-k[x]]=1;
		}
	}
	cout<<-1;
	
}
int main(){
	cin>>n>>nw>>to;
	if(nw==to){
		cout<<0;
		return 0;
	}
	for(int i=1;i<=n;i++)
		cin>>k[i];
	bfs();
	return 0; 
}