调完给大佬关注

#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <cstdio>
#include<queue>
#include<cstring>
using namespace std;

const int N = 210;

queue<int> q;
int k[N], vis[N];


int main() {
	int n, a, b;
	scanf("%d %d %d", &n, &a, &b);
	for (int i = 1; i <= n; i++) {
		scanf("%d", &k[i]);
	}
	q.push(a);
	vis[a] = 1;//标记是否访问过该楼层
	int level = 0;//遍历层次（按钮次数）
	while (!q.empty()) {
		auto t = q.front();
		q.pop();
		if (t == b) {
			cout << level << endl;
			return 0;
		}
		for (int sign = -1; sign <= 1; sign += 2) {
			int floor = t + k[t] * sign;
			if (vis[floor] || floor <= 0 || floor > n)
				continue;
			q.push(floor);
			level++;
			vis[floor]=1;
		}
	}

	cout << -1 << endl;
	return 0;
}