Question

Please write a Python program to play a Sudoku game and show its winning result. This is an application program of using 2-dimensional arrays/lists.   Each array/list is for a game board of 9 x 9. Your program must know how to play Sudoku game and complete the game with a winning result.

The following is a sample test, which must be all your test cases. As you can see, you must pre-load the following 4 games into your arrays/lists.   Please create 4 arrays of 9 x 9 each, and call them G1, G2, G3, and G4 for examples.

Welcome to play the Sudoku real game designed by "Your Name"!

Game 1 is as follows:

123456789

4_6789123

7891_3456

234567891

5678912_4

891234567

_45678912

678912345

912345_78

Game 1 winning result is as follows:

123456789

456789123

789123456

234567891

567891234

891234567

345678912

678912345

912345678

Game 2 is as follows:

_2345678_

_56789_23

7891_3456

23_567891

56789_234

89_23456_

345678_12

_7891_345

91_34567_

Game 2 winning result is as follows:

123456789

456789123

789123456

234567891

567891234

891234567

345678912

678912345

912345678

Game 3 is as follows:

12_456_8_

_5678_123

7_912_456

_34_6_891

567_912_4

8_12345_7

345_78_12

67_9123_5

9_234_67_

Game 3 winning result is as follows:

123456789

456789123

789123456

234567891

567891234

891234567

345678912

678912345

912345678

Game 4 is as follows:

1_34_67_9

_5_78_1_3

_8_12_45_

2_45_78_1

_67_91_3_

8_1_3_56_

_45_7_9_2

6_8_1_34_

_12_456_8

Game 4 winning result is as follows:

123456789

456789123

789123456

234567891

567891234

891234567

345678912

678912345

912345678

Thank you for playing this Sudoku real game designed by "Your Name"!      

Answer 1

# print the Grid
def print_grid(arr):
   for i in range(9):
       for j in range(9):
           print arr[i][j],
       print ('\n')

      
# Function to Find the entry in the Grid that is still not used

def find_empty_location(arr,l):
   for row in range(9):
       for col in range(9):
           if(arr[row][col]==0):
               l[0]=row
               l[1]=col
               return True
   return False

# Returns a boolean which indicates whether any assigned entry
# in the specified row matches the given number.
def used_in_row(arr,row,num):
   for i in range(9):
       if(arr[row][i] == num):
           return True
   return False

# Returns a boolean which indicates whether any assigned entry
# in the specified column matches the given number.
def used_in_col(arr,col,num):
   for i in range(9):
       if(arr[i][col] == num):
           return True
   return False

def used_in_box(arr,row,col,num):
   for i in range(3):
       for j in range(3):
           if(arr[i+row][j+col] == num):
               return True
   return False

# num to the given row,col location.
def check_location_is_safe(arr,row,col,num):
  
   # Check if 'num' is not already placed in current row,
  
   return not used_in_row(arr,row,num) and not used_in_col(arr,col,num) and not used_in_box(arr,row - row%3,col - col%3,num)

def solve_sudoku(arr):
  
   # 'l' is a list variable that keeps the record of row and col in find_empty_location Function     
   l=[0,0]
  
   # If there is no unassigned location, we are done     
   if(not find_empty_location(arr,l)):
       return True
  
   # Assigning list values to row and col that we got from the above Function
   row=l[0]
   col=l[1]
  
   # consider digits 1 to 9
   for num in range(1,10):
      
       # if looks promising
       if(check_location_is_safe(arr,row,col,num)):
          
           # make tentative assignment
           arr[row][col]=num

           # return, if success, ya!
           if(solve_sudoku(arr)):
               return True

           # failure, unmake & try again
           arr[row][col] = 0
          
  
   return False

# Driver main function to test above functions
if __name__=="__main__":
  
   # creating a 2D array for the grid
   grid=[[0 for x in range(9)]for y in range(9)]
  
   # assigning values to the grid
   grid=[[1,2,3,4,5,6,7,8,9],
       [4,0,6,7,8,9,1,2,3],
       [7,8,9,1,0,3,4,5,6],
       [2,3,4,5,6,7,8,9,1],
[5,6,7,8,9,1,2,0,4],
[8,9,1,2,3,4,5,6,7],
[0,4,5,6,7,8,9,1,2],
[6,7,8,9,1,2,3,4,5],
[9,1,2,3,4,5,0,7,8]]
  
   # if success print the grid
   if(solve_sudoku(grid)):
       print_grid(grid)
   else:
       print "No solution exists"