덱 - 10866번

기존에 파이썬에 있는 deque를 사용한다.

 

import sys
from collections import deque
t = int(input())
deque = deque()
for _ in range(t):
    # print(deque)
    instruct = sys.stdin.readline().strip()
    if instruct[:4] == 'size':
        print(len(deque))
    elif instruct[:4] == 'fron':
        if deque:
            print(deque[0])
        else:
            print(-1)
    elif instruct[:4] == 'back':
        if deque:
            print(deque[-1])
        else:
            print(-1)
    elif instruct[:4] == 'empt':
        if deque:
            print(0)
        else:
            print(1)
    elif instruct[:6] == 'push_f':
        deque.appendleft(instruct[11:])
    elif instruct[:6] == 'push_b':
        deque.append(instruct[10:])
    elif instruct[:5] == 'pop_f':
        if deque:
            r = deque.popleft()
            print(r)
        else:
            print(-1)
    elif instruct[:5] == 'pop_b':
        if deque:
            r = deque.pop()
            print(r)
        else:
            print(-1)