백준 알고리즘 10845번

백준링크

자료구조 큐 활용하기

파이썬

from collections import deque
import sys

input = sys.stdin.readline
n = int(input())
dq = deque()

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