CSc 7003, Programming for Data Science (Summer 2021)

Program 3 - Bulls and Cows

Consider numbers in the range 1000 to 9999 which do not have repeating digits. Given two such numbers, we define the number of BULLS and COWS for the pair of numbers as follows:

BULLS = number of digits that appear in the same positions in the two numbers.
COWS = number of digits that appear in both the numbers, but at different positions.

For example, if the two numbers were 2367 and 1327, we have 2 BULLS (for the exact matches for digits 3 and 7) and 1 COW (for the remaining common digit 2 which is in different positions in the two numbers). If the numbers were 9852 and 8926, we have 0 BULLS and 3 COWS and if the numbers were 1234 and 4321, we have 0 BULLS and 4 COWS. It is quite clear that if the two numbers are the same, we have 4 BULLS and 0 COWS.

Write a Python program to play the Bulls and Cows game: Here are two sample runs of the program:

$ python3 Bulls.py

Welcome to the game of BULLS and COWS.
The objective in this game is for you to guess a 4-digit number
The computer responds with how close your guess is to the target
BULLS = # common digits with exact matches and
COWS  = # common digits in wrong position.

Enter guess number 1: 1876
Bulls =  1   Cows =  1
Enter guess number 2: 1183
Your guess should not contain repeating digits
Enter guess number 2: 1596
Bulls =  1   Cows =  2
Enter guess number 3: 1956
Bulls =  3   Cows =  0
Enter guess number 4: 1954
Bulls =  3   Cows =  0
Enter guess number 5: 1958
Bulls =  4   Cows =  0
Congratulations You Won!!

$ python3 Bulls.py

Welcome to the game of BULLS and COWS.
The objective in this game is for you to guess a 4-digit number
The computer responds with how close your guess is to the target
BULLS = # common digits with exact matches and
COWS  = # common digits in wrong position.

Enter guess number 1: 1234
Bulls =  0   Cows =  1
Enter guess number 2: 2345
Bulls =  0   Cows =  0
Enter guess number 3: 1678
Bulls =  0   Cows =  3
Enter guess number 4: 1679
Bulls =  0   Cows =  3
Enter guess number 5: 1670
Bulls =  0   Cows =  4
Enter guess number 6: 6170
Bulls =  0   Cows =  4
Enter guess number 7: 6710
Bulls =  1   Cows =  3
Enter guess number 8: 7610
Bulls =  2   Cows =  2
Enter guess number 9: 7601
Bulls =  1   Cows =  3
Enter guess number 10: 6701
Bulls =  0   Cows =  4
Sorry You ran out of guesses!!
The correct number was:  7016

Writing the following functions will be helpful:

• def extractDigits(num):
  This function takes as input a 4-digit number and returns a tuple of its 4 digits.
• def noRepeatingDigits(num):
  This function takes as input a 4-digit number and returns True is it has no repeating digits and False otherwise.
• def produceTarget():
  This function returns a 4-digit random number that contains no repeating digits. You will need to import the random package.

  from random import *
  
  num = randint(1000,9999)
  

• def numberOfBulls(num1,num2):
  This function takes as input two 4-digit numbers num1 and num2, each between 1000 and 9999 with no repeating digits and returns the number of BULLS for the two numbers.
• def numberOfCows(num1,num2):
  This function takes as input two 4-digit numbers num1 and num2, each between 1000 and 9999 with no repeating digits and returns the number of COWS for the two numbers.

Submit the code under the file Bulls.py.