提问链接

Code

from collections import deque
import sys
read = sys.stdin.readline

q = deque()
for _ in range(int(read())):
    op = read().split()
    if "push" == op[0]:
        q.append(int(op[-1]))
    elif "pop" == op[0]:
        print(q.popleft() if q else -1)
    elif "size" == op[0]:
        print(len(q))
    elif "empty" == op[0]:
        print(0 if q else 1)
    elif "front" == op[0]:
        print(q[0] if q else -1)
    elif "back" == op[0]:
        print(q[-1] if q else -1)

困難事項