I am building a sudoku generator which has randomness in it. In my code, there is a function that generates that sudoku. The problem is that I can't get the two sudoku's to be different
I tried running that function twice, but as expected the two generated sudoku's are exactly the same. I expect that when I copy the entire function and paste it underneath, the sudoku's will be different, but then there would be way too much code.
This is my sudoku generating function, I included some comments for you to better understand what the code does:
let sudoku = [
[0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0],
];
let sudoku2 = JSON.parse(JSON.stringify(sudoku));
let changesMade = false;
let fields = [];
let counter = 0;
let sudoku3;
window.onload = function () {
generateRandomSudoku(25);
print_sudoku(sudoku3, "table1");
print_sudoku(sudoku, "table2");
// this is the code I used to generate the function twice
generateRandomSudoku(25);
print_sudoku(sudoku3, "table3");
print_sudoku(sudoku, "table4");
};
// solves a sudoku
function solveSudoku() {
fill_possible_fields();
changesMade = false;
counter = 0;
while (!sudoku_complete()) {
counter ;
test_rows_and_cols();
test_blocks();
test_possible_fields();
if (!changesMade) {
break;
} else {
changesMade = false;
}
if (counter === 100) {
break;
}
}
}
// returns true if there are two equal numbers in the same row
function duplicateNumberInRow(s, fieldY) {
numbers = new Array();
for (var i = 0; i < 9; i ) {
if (s[i][fieldY] !== 0) {
if (numbers.includes(s[i][fieldY])) {
return true;
} else {
numbers.push(s[i][fieldY]);
}
}
}
return false;
}
// returns true if there are two equal numbers in the same col
function duplicateNumberInCol(s, fieldX) {
numbers = new Array();
for (var i = 0; i < 9; i ) {
if (s[fieldX][i] !== 0) {
if (numbers.includes(s[fieldX][i])) {
return true;
} else {
numbers.push(s[fieldX][i]);
}
}
}
return false;
}
// returns true if there are two equal numbers in the same box
function duplicateNumberInBox(s, fieldX, fieldY) {
boxX = Math.floor(fieldX / 3);
boxY = Math.floor(fieldY / 3);
numbers = new Array();
for (var i = 0; i < 3; i ) {
for (var j = 0; j < 3; j ) {
x = i 3 * boxX;
y = j 3 * boxY;
if (s[x][y] !== 0) {
if (numbers.includes(s[x][y])) {
return true;
} else {
numbers.push(s[x][y]);
}
}
}
}
return false;
}
// returns true if there are two equal numbers in the same row, col or box
function duplicateNumberExists(s, fieldX, fieldY) {
if (duplicateNumberInRow(s, fieldY)) {
return true;
}
if (duplicateNumberInCol(s, fieldX)) {
return true;
}
if (duplicateNumberInBox(s, fieldX, fieldY)) {
return true;
}
return false;
}
// generates a random sudoku with a given amount of numbers in it
function generateRandomSudoku(numbers) {
while (!sudoku_complete() || sudoku_invalid(sudoku)) {
// new empty sudoku
sudoku3 = [
[0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0],
];
sudoku = JSON.parse(JSON.stringify(sudoku3));
// how many numbers are entered already?
let numbersDone = 0;
while (numbersDone < numbers) {
let fieldX = Math.floor(Math.random() * 9);
let fieldY = Math.floor(Math.random() * 9);
let number = Math.floor(Math.random() * 9) 1;
//alert("" fieldX " " fieldY " " number);
if (sudoku3[fieldX][fieldY] === 0) {
sudoku3[fieldX][fieldY] = number;
if (duplicateNumberExists(sudoku3, fieldX, fieldY)) {
sudoku3[fieldX][fieldY] = 0;
continue;
} else {
numbersDone ;
}
//alert("" numbersDone);
}
}
sudoku = JSON.parse(JSON.stringify(sudoku3));
solveSudoku();
}
}
// fills the possible numbers for the fields
function fill_possible_fields() {
for (var i = 0; i < 9; i ) {
fields[i] = [];
}
for (var i = 0; i < 9; i ) {
for (var j = 0; j < 9; j ) {
fields[i][j] = [];
}
}
for (var i = 0; i < 9; i ) {
for (var j = 0; j < 9; j ) {
for (var k = 0; k < 9; k ) {
fields[i][j][k] = k 1;
}
}
}
}
// show the sudoku as a table
function print_sudoku(s, position) {
var tbl = document.createElement("table");
// tbl.style.width = "500px"
// tbl.style.backgroundColor = "blue"
var tbdy = document.createElement("tbody");
tbl.appendChild(tbdy);
for (var i = 0; i < 9; i ) {
var tr = document.createElement("tr");
tbdy.appendChild(tr);
for (var j = 0; j < 9; j ) {
var td = document.createElement("td");
td.appendChild(document.createTextNode("" s[i][j]));
if (s[i][j] === 0) {
td.style.backgroundColor = "white";
td.style.color = "white";
}
tr.appendChild(td);
}
}
document.getElementById(position).appendChild(tbl);
document.getElementById("table1").style.padding = "0px";
}
// tests the possible 9 numbers for a field, if only one is possible then it's entered to the field
function test_possible_fields() {
for (var i = 0; i < 9; i ) {
for (var j = 0; j < 9; j ) {
if (sudoku[i][j] === 0) {
var numbers = 0;
var number = 0;
for (var k = 0; k < 9; k ) {
if (fields[i][j][k] !== 0) {
number = k 1;
numbers ;
}
}
if (numbers === 1) {
sudoku[i][j] = number;
changesMade = true;
}
}
}
}
}
// tests the rows and cols
function test_rows_and_cols() {
for (var i = 0; i < 9; i ) {
for (var j = 0; j < 9; j ) {
if (sudoku[i][j] !== 0) {
var number = sudoku[i][j];
for (var k = 0; k < 9; k ) {
if (sudoku[i][k] === 0) {
if (fields[i][k][number - 1] !== 0) {
changesMade = true;
}
fields[i][k][number - 1] = 0;
}
}
var number = sudoku[i][j];
for (var k = 0; k < 9; k ) {
if (sudoku[k][j] === 0) {
if (fields[k][j][number - 1] !== 0) {
changesMade = true;
}
fields[k][j][number - 1] = 0;
}
}
}
}
}
}
// tests the blocks
function test_blocks() {
for (var k = 0; k < 3; k ) {
for (var l = 0; l < 3; l ) {
for (var i = 0 k * 3; i < 3 k * 3; i ) {
for (var j = 0 l * 3; j < 3 l * 3; j ) {
if (sudoku[i][j] !== 0) {
var number = sudoku[i][j];
for (var a = 0 k * 3; a < 3 k * 3; a ) {
for (var b = 0 l * 3; b < 3 l * 3; b ) {
if (sudoku[a][b] === 0) {
if (fields[a][b][number - 1] !== 0) {
changesMade = true;
}
fields[a][b][number - 1] = 0;
}
}
}
}
}
}
}
}
}
// tests if a sudoku is complete and returns eiter true or false
function sudoku_complete() {
for (var i = 0; i < 9; i ) {
for (var j = 0; j < 9; j ) {
if (sudoku[i][j] === 0) {
return false;
}
}
}
return true;
}
//Tests if there are any duplicate numbers in a sudoku
function sudoku_invalid(s) {
for (var i = 0; i < 9; i ) {
for (var j = 0; j < 9; j ) {
if (duplicateNumberExists(s, i, j)) {
return true;
}
}
}
return false;
}
And this is the html code, which does not contain tables because it is all generated in javascript:
<div id="example-table" style="width: min-content">
<div id="table1"></div>
</div>
<div id="example-table2" style="width: min-content">
<div id="table2"></div>
</div>
<div id="example-table" style="width: min-content">
<div id="table3"></div>
</div>
<div id="example-table2" style="width: min-content">
<div id="table4"></div>
</div>
<br />
<button id="dl-png">Download as png</button>
CodePudding user response：
In your function window.onload = function ()
I added resetSudoku() after you print the first one.
that looks like this:
function resetSudoku(){
sudoku = [
[0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0],
[0, 0, 0, 0, 0, 0, 0, 0, 0],
];
}
It resets the sudoku. I suspect the error is here
function generateRandomSudoku(numbers) {
while (!sudoku_complete() || sudoku_invalid(sudoku)) {}
you check if the sudoku is not completed but if you do not reset sudoku, the sudoku is already completed.