Take the digits 1,2,3 up to 9 in numerical order and put either a plus sign or a minus sign or neither between the digits to make a sum that adds up to 100. For example, one way of achieving this is: 1 + 2 + 34 - 5 + 67 - 8 + 9 = 100, which uses six plusses and minuses. What is the fewest number of plusses and minuses you need to do this?

brain_tester_of_the_day_20170703.py

# pow(3, 8) = 6561
options = ['', '+', '-']
for i in options:
     for j in options:
         for k in options:
             for l in options:
                 for m in options:
                     for n in options:
                         for o in options:
                             for p in options:
                                 if eval('1' + i + '2' + j + '3' + k + '4' + l + '5' + m + '6' + n + '7' + o + '8' + p + '9') == 100:
                                     print '1' + i + '2' + j + '3' + k + '4' + l + '5' + m + '6' + n + '7' + o + '8' + p + '9'