题解 | #24点运算#

import re

def solution():
    def dfs(nums,exp):
        if not nums:
            return False
        if len(nums)==1:
            if nums[0]==24:
                return exp
            else:
                return False
        for i,a in enumerate(nums):
            for j,b in enumerate(nums):
                if i!=j:
                    subnums = []
                    for k,c in enumerate(nums):
                        if k!=i and k!=j:
                            subnums.append(c)
                    for k in range(4):
                        temp = exp
                        if i>j and k<2:
                            continue
                        if k==0:
                            subnums.append(a+b)
                            exp += '{}+{}%'.format(a,b)
                        if k==1:
                            subnums.append(a*b)
                            exp += '{}*{}%'.format(a,b)
                        if k==2:
                            subnums.append(a-b)
                            exp += '{}-{}%'.format(a,b)
                        if k==3:
                            if b!=0:
                                subnums.append(a//b)
                                exp += '{}/{}%'.format(a,b)
                            else:
                                continue
                        if dfs(subnums,exp):
                            return dfs(subnums,exp)
                        subnums.pop()
                        exp = temp
        return False

    nums = list(input().split())
    copys = nums.copy()
    value = {'J':11,'Q':12,'K':13,'A':1}
    if 'joker' in nums:
        print('ERROR')
        return
    else:
        for i in range(len(nums)):
            if nums[i].isdigit():
                nums[i] = int(nums[i])
            else:
                nums[i] = value[nums[i]]
    maps2 = {'+'}
    if dfs(nums,''):
        exp = dfs(nums,'')
        cell = exp.strip('%').split('%')
        res = cell[-1]
        ws = re.split('[+]|[*]|[-]|[/]',res)

        if eval(cell[0])==eval(ws[0]):
            res = res.replace(ws[0],'({})'.format(cell[0]))
        elif eval(cell[0])==eval(ws[1]):
            res = res.replace(ws[1],'({})'.format(cell[0]))
        if eval(cell[1])==eval(ws[0]):
            res = res.replace(ws[0],'({})'.format(cell[1]))
        elif eval(cell[1])==eval(ws[1]):
            res = res.replace(ws[1],'({})'.format(cell[1]))
        if '13' in res:
            res = res.replace('13','K')
        if '12' in res:
            res = res.replace('12','Q')
        if '11' in res:
            res = res.replace('11','J')
        if '1' in res:
            res = res.replace('1','A')
        compare = ' '.join(re.split('[)]|[(]|[+]|[*]|[-]|[/]',res)).split()

        if compare!=copys:
            print('NONE')
        else:
            print(res)
    else:
        print('NONE')

solution()