[프로그래머스/Programmers] 수식 최대화 - Python

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코딩테스트 연습 - 수식 최대화

 

Solution

from itertools import permutations

def calc(oper, n, expression):
    if expression.isdigit():
        return str(expression)
    else:
        if oper[n] == '*':
            split_expression = expression.split('*')
            temp = []

            for i in range(len(split_expression)):
                temp.append(calc(oper, n + 1, split_expression[i]))

            return str(eval('*'.join(temp)))

        elif oper[n] == '+':
            split_expression = expression.split('+')
            temp = []

            for i in range(len(split_expression)):
                temp.append(calc(oper, n + 1, split_expression[i]))

            return str(eval('+'.join(temp)))

        elif oper[n] == '-':
            split_expression = expression.split('-')
            temp = []

            for i in range(len(split_expression)):
                temp.append(calc(oper, n + 1, split_expression[i]))

            return str(eval('-'.join(temp)))


def solution(expression):
    answer = 0

    oper = ['*', '+', '-']
    oper = list(permutations(oper, 3))

    for i in range(len(oper)):
        result = abs(int(calc(oper[i], 0, expression)))

        answer = max(answer, result)

    return answer

🔑 key point: Recursive Function
📌 Tip: itertools.permutataions()

 

Other Solution

from itertools import permutations

def solution(expression):
    oper = ['+', '-', '*']
    oper = list(permutations(oper, 3))
    answer = []

    for op in oper:
        a = op[0]
        b = op[1]
        temp_list = []

        for e in expression.split(a):
            temp = [f'({i})' for i in e.split(b)]
            temp_list.append(f'({b.join(temp)})')

        answer.append(abs(eval(a.join(temp_list))))

    return max(answer)

🔑 key point: [f'({i})' for i in e.split(b)]
📌 Tip: itertools.permutataions()