mdame's impossible problem

solve.py

#!/usr/bin/python3
import itertools

operations = []

# thanks to https://www.geeksforgeeks.org/print-all-combinations-of-given-length/
# for reminding (telling) me how to permute every possible string of length k that can be formed from a set of n characters

# The method that prints all  
# possible strings of length k. 
# It is mainly a wrapper over  
# recursive function printAllKLengthRec() 
def printAllKLength(set, k): 
  
    n = len(set)  
    printAllKLengthRec(set, [], n, k) 
  
# The main recursive method 
# to print all possible  
# strings of length k 
def printAllKLengthRec(set, prefix, n, k): 
    # Base case: k is 0, 
    # print prefix 
    if (k == 0) : 
        operations.append(prefix)
        return
  
    # One by one add all characters  
    # from set and recursively  
    # call for k equals to k-1 
    for i in range(n): 
  
        # Next character of input added 
        newPrefix = prefix.copy()
        newPrefix.append(set[i])
          
        # k is decreased, because  
        # we have added a new character 
        printAllKLengthRec(set, newPrefix, n, k - 1) 

# Driver Code 
if __name__ == "__main__": 
    ops = ['+', '*', '-', '/']
    k = 3
    printAllKLength(ops, k) 

    for num_perm in itertools.permutations(['2', '8', '3', '12']):
        for op in operations:
            equation = ""
            for i in range(0,3):
                equation += num_perm[i] + op[i]
            equation += num_perm[3]
            res = eval(equation)
            if res == 33:
                print(equation, "=", res)