AcWing BFS相关问题 1100. 抓住那头牛

import sys
sys.stdin = open('data.txt', 'r')'''
简单BFS找最短路长度
'''from collections import deque
m, n = map(int, input().split())def bfs(m, n):que = deque()que.append(m)visited = {m}step = 0while len(que) > 0:node_num = len(que)for _ in range(node_num):cur = que.popleft()if cur-1 >= 0 and cur-1 not in visited:if cur-1 == n:return step+1visited.add(cur-1)que.append(cur-1)if cur < n:if cur+1 not in visited:if cur+1 == n:return step+1visited.add(cur + 1)que.append(cur + 1)if cur * 2 not in visited:if cur*2 == n:return step+1visited.add(cur * 2)que.append(cur * 2)step += 1return -1print(bfs(m, n))