[백준] 10845 - 큐 (파이썬)

https://www.acmicpc.net/problem/10845

10845번: 큐

 

import sys
N = int(sys.stdin.readline())
commands = []
[commands.append(sys.stdin.readline().split()) for _ in range(N)]

queue = []
for command in commands:
    if command[0] == 'push':
        queue.append(int(command[1]))
    elif command[0] == 'pop':
        if queue:
            print(queue.pop(0))
        else:
            print(-1)
    elif command[0] == 'size':
        print(len(queue))
    elif command[0] == 'empty':
        if queue:
            print(0)
        else:
            print(1)
    elif command[0] == 'front':   
        if queue:
            print(queue[0])
        else:
            print(-1)
    else: # back  
        if queue:
            print(queue[-1])
        else:
            print(-1)