Sudoku Cell

A Sudoku puzzle contains 81 "cells" of numbers in a 9 x 9 grid. One helpful approach to solving a Sudoku puzzle is to make a class that represents each cell in the puzzle along with three different formats of the Sudoku puzzle representing each region type:

• row
• column
• box

Keep in mind that the definition for a cell's region is as follows:

• Each cell has a "region" which contains all values in the cell's row, column, and box excluding the cell itself.

Task I

Create a class Cell with the following attributes:

• val: The value of the cell.
• rLocation: The location of the cell in rowData with the format (r0, r1).

The class should have the following methods:

• convIndices(): convert the row indices into column and box index formats.
• getRegions(regionData): get the cell's region.

Task II

Create a function getRegionData(puzzle):

• The function should return a list containing three different regional representations of the puzzle (as described below).
• The function should create and store Cell instances in each nested list.

Puzzle Format

The Sudoku puzzle will be formatted in a 9 x 9 list where each nested list is a row in the puzzle:

puzzle = [
  [0, 0, 0, 0, 0, 0, 9, 0, 6],
  [3, 0, 2, 0, 6, 0, 0, 0, 0],
  [8, 0, 0, 7, 0, 3, 0, 0, 5],
  [0, 0, 3, 9, 0, 6, 0, 0, 0],
  [6, 0, 0, 0, 5, 0, 0, 0, 0],
  [0, 0, 4, 8, 0, 1, 0, 0, 0],
  [7, 0, 0, 4, 0, 8, 0, 0, 2],
  [5, 0, 8, 0, 9, 0, 0, 0, 0],
  [0, 0, 0, 0, 0, 0, 7, 0, 1]
]

Note: Zeros represent unsolved cells.

The getRegionData(puzzle) Function

This function should return a list containing the three lists representing different region types of the puzzle. For these purposes, these lists will be referred to as:

• rowData: same format as puzzle.
• colData: 2D list of columns.
• boxData: 2D list of boxes ordered as shown below.

Note: Each box contains another 3 x 3 box ordered like its container. The numbers shown above represent indices that correspond to the following list structure:

• [[0], ... , [8]] where each nested list is [0, ... , 8]

The convIndices() Method

This method should be called on initialization and create two new attributes:

• cLocation: the location of the cell in colData with the format (c0, c1)
• bLocation: the location of the cell in boxData with the format (b0, b1)

Hint: rowData[r0][r1] = colData[c0][c1] = boxData[b0][b1]

Example #1

cell = Cell(_, (1, 2))

cell.rLocation
(1, 2)

cell.cLocation
(2, 1)

cell.bLocation
(0, 5)

The getRegions(regionData) Method

This method should take in regionData and create one new attribute:

• regions: a 2D list containing the row, column, and box region for the cell.

Note: Each cell's region should contain Cell instances excluding the cell.

Example #2

regionData = getRegionData(puzzle)
cell.getRegions(regionData)

cell.regions
[[row region], [col region], [box region]]

Notes

N/A