[백준] 10845번 : 큐 - Python(파이썬)

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

class Queue:
    def __init__(self):
        self.queue = []

    def push(self,num):
        self.queue.append(num)

    def pop(self):
        if len(self.queue) == 0:
            return -1
        else:
            ans = self.queue[0]
            del self.queue[0]
            return ans

    def size(self):
        return len(self.queue)

    def empty(self):
        if len(self.queue) == 0:
            return 1
        else:
            return 0

    def front(self):
        if len(self.queue) == 0:
            return -1
        else:
            return self.queue[0]

    def back(self):
        if len(self.queue) == 0:
            return -1
        else:
            return self.queue[-1]


n=int(input())
t=Queue()
an=[]
count=0
for i in range(n):
    arr = input().split()
    st = arr[0]
    if st == "push":
        t.push(arr[1])
    elif st == "pop":
        an.append(t.pop())
        count+=1
    elif st == "size":
        an.append(t.size())
        count+=1
    elif st == "empty":
        an.append(t.empty())
        count+=1
    elif st == "front":
        an.append(t.front())
        count+=1
    elif st == "back":
        an.append(t.back())
        count+=1

for i in range(count):
    print(an[i])