sudokuconv

README

sudokuconv

Package sudokuconv contains helpers to convert solved 9x9 sudokus to compact byte slices.

It will be used by https://sudokoin.com soon to add meta information to transactions.

Documentation

Overview

Package sudokuconv contains helpers to convert solved 9x9 sudokus to compact byte slices.

Example

package main

import (
	"fmt"
	"reflect"

	"github.com/jraedisch/sudokuconv"
)

func main() {
	board := [9][9]int{
		{9, 8, 7, 6, 5, 4, 3, 2, 1},
		{6, 5, 4, 3, 2, 1, 9, 8, 7},
		{3, 2, 1, 9, 8, 7, 6, 5, 4},
		{8, 9, 6, 7, 4, 5, 2, 1, 3},
		{7, 4, 5, 2, 1, 3, 8, 9, 6},
		{2, 1, 3, 8, 9, 6, 7, 4, 5},
		{5, 7, 9, 4, 6, 8, 1, 3, 2},
		{4, 6, 8, 1, 3, 2, 5, 7, 9},
		{1, 3, 2, 5, 7, 9, 4, 6, 8},
	}

	bytes, err := sudokuconv.ToBytes(board)

	if err != nil {
		// board is not solved correctly
	}

	board2, err := sudokuconv.FromBytes(bytes)

	if err != nil {
		// bytes are corrupted
	}

	fmt.Println(reflect.DeepEqual(board, board2))
}

Output:

true

Index

• func FromBytes(bytes []byte) ([9][9]int, error)
• func ToBytes(board [9][9]int) ([]byte, error)

Examples

• Package

Functions

func FromBytes

func FromBytes(bytes []byte) ([9][9]int, error)

FromBytes converts bytes (see ToBytes) back to board. An error is returned iff the provided bytes are malformed.

func ToBytes

func ToBytes(board [9][9]int) ([]byte, error)

ToBytes converts a 9x9 sudoku board into a compact bit representation. Size is 23 or 24 bytes depending on where the 9s are. The returned byte slice contains 4 bits for the row where the 9 is in the last column. Then follow 3 bits for each of the other eight columns containing 9s. Then the other symbols are converted and appended as 3 bits each. For this, 1-8 are converted to 0-7. The last row and column are left out since they can trivially be computed. An error is returned iff the provided board is not correctly solved.