J'ai construit un algorithme de retour arrière de solveur de sudoku en python juste pour découvrir qu'il ne fonctionne pas. J'ai regardé des exemples sur internet et j'ai vu qu'il n'y a qu'une seule chose qu'ils font différemment, par rapport au mien. J'ai changé mon code en conséquence et mon programme fonctionne maintenant très bien.Solveur Sudoku Clarification de l'algorithme Python nécessaire
Voici le code de travail:
sudoku = []
next_empty_pos = [0,0]
# Check if the number is already used in the given row
def valid_in_row(number,row):
for i in range(9):
if(sudoku[row][i] == number):
return False
return True
# Check if the number is already used in the given column
def valid_in_col(number,col):
for i in range(9):
if(sudoku[i][col] == number):
return False;
return True;
# Check if the number is already used in the given 3x3 box
def valid_in_box(number,row,col):
# Find where 3x3 row and col starts
col_start = col-col%3
row_start = row-row%3
# Loop through the 3 columns and 3 rows
for i in range(3):
for z in range(3):
if(sudoku[i+row_start][z+col_start] == number):
return False
return True
# Check if the position is valid for the given number by checking all three conditions above
def position_valid(number,row,col):
return valid_in_row(number,row) and valid_in_col(number,col) and valid_in_box(number,row,col)
# Find if there are any empty cells left and assign the next empty cell
def empty_position_exists():
for row in range(9):
for col in range(9):
if(sudoku[row][col] == 0):
global next_empty_pos
next_empty_pos = [row,col]
return True
return False
# Solve the sudoku
def solve_sudoku():
# If there are no more empty cells, we are finished
if(not empty_position_exists()):
return True
row=next_empty_pos[0]
col=next_empty_pos[1]
# Try numbers from 1
for posssible_number in range(1,10):
if(position_valid(posssible_number,row,col)):
sudoku[row][col] = posssible_number
# If the next function call evalutes to true, then this should be true as well
if(solve_sudoku()):
return True
# If the above did not work then, set the number back to 0 (unassgined)
sudoku[row][col] = 0
# Return false if none of the numbers were good
return False
La différence à mon code d'origine a été que je passe next_empty_pos[0]
et next_empty_pos[1]
directement dans ma fonction solve_sudoku
et non les déclarant séparés row
et col
variables extérieures de la boucle for.
Ma fonction ressemblait à ceci:
# Solve the sudoku
def solve_sudoku():
# If there are no more empty cells, we are finished
if(not empty_position_exists()):
return True
# Try numbers from 1
for posssible_number in range(1,10):
if(position_valid(posssible_number,next_empty_pos[0],next_empty_pos[1])):
sudoku[next_empty_pos[0]][next_empty_pos[1]] = posssible_number
# If the next function call evalutes to true, then this should be true as well
if(solve_sudoku()):
return True
# If the above did not work then, set the number back to 0 (unassgined)
sudoku[next_empty_pos[0]][next_empty_pos[1]] = 0
# Return false if none of the numbers were good
return False
Quelqu'un pourrait-il expliquer pourquoi ma version ne fonctionnait pas?
Merci d'avance.
Oui, c'est logique. Je vous remercie! –