sudoku_solver/sudoku_solver.py

# Sudoku: 9x9 Spielfeld. Auf jedem Feld ist eine Liste mit möglichen Werten.
# Enthält diese Liste nur einen Wert, ist das der gesuchte Wert für das Feld.

gamefield = [
    [[],[7],[],[5],[8],[3],[],[2],[]],
    [[],[5],[9],[2],[],[],[3],[],[]],
    [[3],[4],[],[],[],[6],[5],[],[7]],
    [[7],[9],[5],[],[],[],[6],[3],[2]],
    [[],[],[3],[6],[9],[7],[1],[],[]],
    [[6],[8],[],[],[],[2],[7],[],[]],
    [[9],[1],[4],[8],[3],[5],[],[7],[6]],
    [[],[3],[],[7],[],[1],[4],[9],[5]],
    [[5],[6],[7],[4],[2],[9],[],[1],[3]]
];

def fill_empty_fields_with_possible_values():
    y = 0
    for row in gamefield:
        x = 0
        for field in row:
            if(len(field) == 0):
                field = [1,2,3,4,5,6,7,8,9]
                row[x] = field
            x = x + 1
        gamefield[y] = row
        y = y + 1

def print_sudoku():
    for row in gamefield:
        for field in row:
            if(len(field) == 1):
                print(field, end='')
            else:
                print('[ ]', end='')
        print('')

def solve_by_cell_check():
    # for each cell
    y = 0
    for row in gamefield:
        x = 0
        for field in row:
            # if value is already defined, check next value
            if(len(field) == 1):
                continue
            # for each possible value
            for possible_value in field:
                print("check value", possible_value, "at (",x,"/",y,") : ",gamefield[y][x])
                if(check_row_for_value(x, y, possible_value) or
                   check_column_for_value(x, y, possible_value) or 
                   check_3x3_for_value(x, y, possible_value)):
                    # if yes, remove it from possible values
                    remove_from_possible_values(x, y, possible_value)
                    print(gamefield[y][x])
                    # reset x and break to check that field again
                    x = x - 1
                    break
            x = x + 1
        y = y + 1

def remove_from_possible_values(x, y, value):
    gamefield[y][x].remove(value)

# i do not explicitely skip the field itself because it is skipped by len check
def check_row_for_value(x, y, value):
    for field in gamefield[y]:
        if len(field) == 1:
            if field[0] == value:
                return True 
    return False

def check_column_for_value(x, y, value):
    return False

def check_3x3_for_value(x, y, value):
    return False

fill_empty_fields_with_possible_values()
#print(gamefield[0][0])
print_sudoku()
solve_by_cell_check()
#print(gamefield[0][0])
#print_sudoku()