[백준][큐 & 덱] 18258. 큐 2 (파이썬/Python)

<오답>

import sys
input = sys.stdin.readline
def push(x):
    return queue.append(x)
def pop():
    if len(queue) > 0:
        return queue.pop(0)
    return -1
def size():
    return len(queue)
def empty():
    if len(queue) > 0:
        return 0
    return 1
def front():
    if len(queue) > 0:
        return queue[0]
    return -1
def back():
    if len(queue) > 0:
        return queue[-1]
    return -1

n = int(input())
queue = []
for _ in range(n):
    command = input().split()
    if command[0] == "push":
        push(command[1])
    elif command[0] == "pop":
        print(pop())
    elif command[0] == "size":
        print(size())
    elif command[0] == "empty":
        print(empty())
    elif command[0] == "front":
        print(front())
    else:
        print(back())

#시간초과

 

 

<정답>

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

n = int(input())
queue = deque()

for _ in range(n):
    command = input().split()
    if command[0] == 'push':
        queue.append(command[1])
        
    elif command[0] == 'pop':
        if len(queue)>0:
            print(queue.popleft())
        else:
            print(-1)
            
    elif command[0] == 'size':
        print(len(queue))
        
    elif command[0] == 'empty':
        if len(queue) == 0:
            print(1)
        else:
            print(0)
    elif command[0] == 'front':
        if queue:
            print(queue[0])
        else:
            print(-1)
    elif command[0] == 'back':
        if queue:
            print(queue[-1])
        else:
            print(-1)

#데크를 사용하여 해결 했다.

#데크 사용 없이도 풀이 가능한 문제임.

#pop 함수때문인지 위의 풀이는 틀림