team-lab-quiz-2010

import itertools
import re

org_str = '2ABACBDEDFDFDFDCBACDAFB2'
candidates = ['0', '3', '4', '5', '6', '7', '8', '9']
operators = ['+', '-', '*', '/', '=']
candidates.extend(operators)

simple_op_check = re.compile(r'[*+-/=][*+-/=0]')

for combination in itertools.combinations(''.join(candidates), 5):
    for permutation in itertools.permutations('ABCDEF', 6):
        replaced_str = org_str
        for src, dst in zip(permutation, combination):
            replaced_str = replaced_str.replace(src, dst)
        replaced_str = replaced_str.replace(permutation[-1], '1')

        if(simple_op_check.search(replaced_str)):
            continue

        equation = replaced_str.split('=')
        if len(equation) != 2:
            continue

        ans = [eval(exp) for exp in equation]
        ans = set(ans)
        if len(ans) == 1:
            print replaced_str