인프런 커뮤니티 질문&답변

n = input()

stack = []
result = ''

for i in n:
    if i.isnumeric():
        result += i

    else:
        if len(stack) == 0:
            stack.append(i)
            continue

        if i == '*' or i == '/':
            if stack[-1] == '*' or stack[-1] == '/':
                result += stack[-1]
                stack.pop()
            stack.append(i)
            
        elif i == '+' or i == '-':
            while stack and stack[-1] != '(':
                result += stack[-1]
                stack.pop()
            stack.append(i)

        elif i == '(':
            stack.append(i)

        elif i == ')':
            while stack and stack[-1] != '(':
                result += stack[-1]
                stack.pop()
            stack.pop()

for x in stack[::-1]:
    if x != '(':
        result += x

print(result)