Answer
code
Work Step by Step
# 11.24 (Check Sudoku solution) Listing 11.7 checks whether a solution is valid by checking
# whether every number is valid in the grid. Rewrite the program by checking
# whether every row, column, and box has the numbers 1 to 9.
def main():
# Read a solution
grid = readASolution()
if isValidGrid(grid):
print("Valid solution")
else:
print("Invalid solution")
# Read a solution from the console
def readASolution():
print("Enter a Sudoku puzzle solution:")
grid = []
for i in range(9):
line = input().strip().split()
grid.append([eval(x) for x in line])
return grid
# Check whether the fixed cells of the grid are valid
def isValidGrid(grid):
# Check whether each row has numbers 1 through 9
for i in range(9):
if not is1To9(grid[i]): # If grid[i] does not contain 1 through 9
return False
# Check whether each column has numbers 1 through 9
for j in range(9):
# Obtain a column in the one-dimensional array
column = []
for i in range(9):
column.append(grid[i][j])
if not is1To9(column): # If column does not contain 1 through 9
return False
# Check whether each 3 by 3 box has numbers 1 through 9
for i in range(3):
for j in range(3):
# The starting element in a small 3 by 3 box
k = 0
list = 9 * [0] # Get all numbers in the box to list
for row in range(i * 3, i * 3 + 3):
for column in range(j * 3, j * 3 + 3):
list[k] = grid[row][column]
k += 1
if not is1To9(list): # If the list does not contain 1 through 9
return False
return True # The fixed cells are valid
# Check whether the one-dimensional array contains 1 through 9
def is1To9(list):
# Make a copy of the array
temp = [x for x in list]
# Sort the array
temp.sort()
# Check if list contains 1, 2, 3, through 9
return temp == [1, 2, 3, 4, 5, 6, 7, 8, 9]
main()
