[백준] 1935번 (python 파이썬)

https://www.acmicpc.net/problem/1935

1935번: 후위 표기식2

 

import sys

n = int(sys.stdin.readline().strip())
exp = sys.stdin.readline().strip()
d = {}
stack = []
for i in range(n):
  d[chr(65+i)] = int(sys.stdin.readline().strip())

for c in exp:
  if c.isalpha():  # 값이면
    stack.append(d[c])
  else:        # 연산자면
    num2 = stack.pop()
    num1 = stack.pop()
    if c == "+":
      stack.append(num1+num2)
    elif c == "-":
      stack.append(num1-num2)
    elif c == "*":
      stack.append(num1*num2)
    elif c == "/":
      stack.append(num1/num2)
print(f'{stack.pop():.2f}')