gistfile1.py

# Kevin Cao
# March 9, 2015

# define intro function
def intro():
    # give rules
    print ("This is a puzzle favored by Einstein. \nYou will be asked to enter a three digit number, \nwhere the hundred's digit differs from the one's digit \nby at least two. \nThe procedure will always yield 1089.")
# define function einstein
def main():
    # prompt user for number
    
    
    # define digits for number

    
    # define is_valid
    def is_valid(num):
        # set conditionals for number to be 3 digits and the properties of the hundreds and tens digits
        if num >= 100 and num <= 1000:
            if hundreds / 100 > ones:
                if (hundreds / 100)- ones >= 2:
                    return True
                else:
                    return False
            if hundreds / 100 < ones:
                if ones - (hundreds / 100) >= 2:
                    return True
                else:
                    return False
        else:
            return False

    while True:
        number = int(input("Please enter a number: "))
        hundreds = (number // 100) * 100
        tens = ((number - hundreds) // 10) * 10
        ones = number - hundreds - tens
            # set error message
        if is_valid(number):
                break
        else:
                print ("The number you have provided does not abide by the rules. \nPlease provide a 3 digit number where the hundreds digit differs from the one's digit by at least 2.")


    # define reverse function
    def reverse(num):
        # define digits for num
        hundreds = (num // 100) * 100
        tens = ((num - hundreds) // 10) * 10
        ones = num - hundreds - tens

        # reverse values
        r_hundreds = hundreds // 100
        r_ones = ones * 100

        # reversed num
        r_num = r_ones + tens + r_hundreds

        # print input and reverse
        return r_num

    r_num = reverse(number)

    # print the number and its reverse
    print ("Your number is", number)
    print ("The reverse of your number is", r_num)

    # define difference variable
    difference = 0

    # define conditional for positive difference
    if number > r_num:
        difference = number - r_num
    elif r_num > number:
        difference = r_num - number

    r_difference = reverse(difference)

    # print the difference 
    print ("The difference between your first number and the reverse is", difference)
    print ("The reverse of the difference is", r_difference)

    # sum of difference and reversed difference
    thousand_eighty_nine = difference + r_difference

    # print the sum
    print ("The sum of your difference and the reverse of your difference is", thousand_eighty_nine)

    print ("Your answer will always be 1089 because of this method.")

# call function
main()