백준 파이썬 10828 스택

 

 

 

 

 

 

 

 

내 풀이

import sys
 
class Stack:
    def __init__(self):
        self.len = 0
        self.list = []
 
    def push(self,x):
        self.list.append(x)
        self.len += 1
 
    def pop(self):
        if self.len == 0:
            return -1
        pop_result = self.list[self.len - 1]
        del self.list[self.len - 1]
        self.len -= 1
        return pop_result
 
    def size(self):
        return self.len
 
    def empty(self):
        return 1 if self.len == 0 else 0
 
    def top(self):
        if self.len == 0:
            return -1
        else:
            return self.list[self.len - 1]
 
 
n = int(sys.stdin.readline())
 
stack = Stack()
 
while n > 0:
    n -= 1
    a = sys.stdin.readline().split()
    if a[0] == 'push':
        stack.push(a[1])
    elif a[0] == 'top':
        print(stack.top())
    elif a[0] == 'size':
        print(stack.size())
    elif a[0] == 'empty':
        print(stack.empty())
    elif a[0] == 'pop':
        print(stack.pop())