Sudoku Checker in Python

Sudoku is a logic based number-placement puzzle, The objective of the puzzle is to fill a n * n grid with digits so that :-

• Each column of the square contains each of the numbers from 1 to n exactly once.
• Each row of the square contains each of the numbers from 1 to n exactly once.

The Code

Code:

correct = [[1,3,2],
           [2,1,3],
           [3,2,1]]

incorrect = [[1,2,4,3],
             [2,3,1,3],
             [3,1,2,3],
             [4,2,2,4]]


def check_sudoku(game):
    n = len(game)
    if n < 1:
        return False
    for i in range(0, n):
        horizontal = []
        vertical = []
        for k in range(0, n):
            #vertical check
            if game[k][i] in vertical:
                return False
            vertical.append(game[k][i])

            if game[i][k] in horizontal:
                return False
            horizontal.append(game[i][k])
    return True

print check_sudoku(correct)
print check_sudoku(incorrect)

Output :-

Code:

True
False

Conclusion

The above code would work for any sudoku grid, like 3 x 3, 4 x 4, 9 x 9 etc. Now next time someone asks you to check his/her solved sudoku just feed that into this program and give them the answer , That's easy :pleased: isn't it?