#!/usr/bin/env python
#
# Sudoku checker
# Take 9 lists of 9 numbers and check whether or not it is a valid sudoku
def get_sudoku():
sudoku = []
print 'Input the sudoku'
for i in range(9):
sudoku.append(raw_input().split(' '))
if len(sudoku[i]) != 9:
print 'Really? Since when was a sudoku row not 9 numbers?'
return False
for n in sudoku[i]:
if (len(n) !=1) or (not n.isdigit()) or n=='0': # negative entries & entries greater than 9(2 or more digits), not digits or less than 1 are weeded out
print 'Enter a valid sudoku!'
return False
return sudoku
def check_sudoku(sudoku):
if not sudoku:
return False
row=[]
column=[]
box=[]
for i in range(9):
row.append([])
column.append([])
box.append([])
for r in sudoku:
i= sudoku.index(r)
for c in r:
j= r.index(c)
if c in row[i] or c in column[j] or c in box[(i/3)*3+j/3]:
return False
else:
row[i].append(c)
column[j].append(c)
box[(i/3)*3+j/3].append(c)
return True
s = get_sudoku()
print check_sudoku(s)

My solution has two functions, get_sudoku(), which takes a sudoku as input from the user, and check_sudoku(list), which checks the sudoku for correctness, well checks for a few things, a lot of the checking work is shared by the get_sudoku function.

## 5 Responses

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

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

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

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

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

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

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

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

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

and the program gives an error.

5 3 4 6 7 8 9 1 2

6 7 2 1 9 5 3 4 8

1 9 8 3 4 2 5 6 7

8 5 9 7 6 1 4 2 3

4 2 6 8 5 3 7 9 1

7 1 3 9 2 4 8 5 6

9 6 1 5 3 7 2 8 4

2 8 7 4 1 9 6 3 5

3 4 5 2 8 6 1 7 9

The input to `check_sudoku` needs to be an array of arrays. So if you are calling `check_sudoku` directly, then try using this

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

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

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

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

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

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

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

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

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

Traceback (most recent call last):

File "C:\Users\User\Downloads\try5.py", line 38, in <module>

print (check_sudoku(s))

File "C:\Users\User\Downloads\try5.py", line 29, in check_sudoku

if c in row[i] or c in column[j] or c in box[(i/3)*3+j/3]:

TypeError: list indices must be integers or slices, not float

And if I try with the second one I get that I haven't entered 9 numbers in the row.

I should probably mention that i am working on a python 3.6.2.

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