Question

Given a cryptarithm puzzle using four letters, such as ['a','b','cd'], and a list of the four solution digits, such as [1,4,6,8], figure out the mapping of digits to letters that solves the cryptarithm. There will be two addends, so the length of the puzzle list is 3. The solution should be expressed as a

string; for example, '6+8=14

This is the algorithm to follow

            Create a list of the four distinct letters used in the puzzle. Example: ['a','b','c','d']

            For each number in the solution digit list,

                        Let the first letter from the letter list be associated with that number

                        For each remaining number in the solution digit list,

                                    Let the second letter in the letter list be associated with that number

                                    For each remaining number in the solution digit list,

                                                Let the third letter be associated with this number

                                                Let the fourth letter be associated with the other number.

                                                Check to see if these number associations solve the puzzle or not

                                                If so, return the solution in the required format

            If no solutions are found, return a helpful message.

Type the possible code.

def solve(puzzle,digitList):

.

Answer 1

Please find the below code for the above mentioned assignment, I hope this will help you if yes, give me a thumps up!

def solve(puzzle, digitList):
    distinct_letters = []
    letter_association = {}
    solution = []
    for i in puzzle:
        for x in i:
            if x not in distinct_letters:
                distinct_letters.append(x)
                letter_association[x] = ""
    for i in digitList:
        letter_association[distinct_letters[0]] = digitList[digitList.index(i)]
        for j in (list(list(set(digitList) - {i}))):
            letter_association[distinct_letters[1]] = digitList[digitList.index(j)]
            for k in (list(list(set(digitList) - {i, j}))):
                letter_association[distinct_letters[2]] = digitList[digitList.index(k)]
                for l in (list(list(set(digitList) - {i, j, k}))):
                    letter_association[distinct_letters[3]] = digitList[digitList.index(l)]
                    expr_1 = puzzle[0]
                    expr_2 = puzzle[1]
                    expr_3 = puzzle[2]
                    int_1 = ""
                    int_2 = ""
                    int_3 = ""
                    for z in expr_1:
                        int_1 += str(letter_association[z])
                    int_1 = int(int_1)
                    for z in expr_2:
                        int_2 += str(letter_association[z])
                    int_2 = int(int_2)
                    for z in expr_3:
                        int_3 += str(letter_association[z])
                    int_3 = int(int_3)
                    if int_1 + int_2 == int_3:
                        solution.append("{}+{}={}".format(int_1, int_2, int_3))
    if len(solution) == 0:
        print("No Solutions found for the puzzle!!")
        return [-1]
    return solution


def testCase(testNumber, puzzle, digits, expectedList):
    actualResult = solve(puzzle, digits)
    if sorted(actualResult) == sorted(expectedList):
        print("Test ", testNumber, " passed.")
    else:
        print("Test ", testNumber, " failed. Expected one of: {} Actual: {}".format(expectedList, actualResult))


def test():
    testCase(1, ['a', 'b', 'cd'], [1, 4, 6, 8], ['6+8=14', '8+6=14'])
    testCase(2, ['q', 'r', 'st'], [5, 2, 1, 7], ['5+7=12', '7+5=12'])
    testCase(3, ['xyz', 'zx', 'xzw'], [4, 7, 0, 3], ['403+34=437', '304+43=347'])

test()