Murhaf Sousli Murhaf Sousli - 2 months ago 40
Javascript Question

How to adjust randomization level javascript

I'm developing 8 puzzle game using javascript, I shuffle the tiles by shuffling the puzzle tiles array

enter image description here

var shuffleArray = (array) => {
var currentIndex = array.length, temporaryValue, randomIndex;
while (0 !== currentIndex) {
randomIndex = Math.floor(Math.random() * currentIndex);
currentIndex -= 1;
temporaryValue = array[currentIndex];
array[currentIndex] = array[randomIndex];
array[randomIndex] = temporaryValue;
return array;

I want to give the user the option to choose difficulty: easy, medium, hard,
How can I implment this?


I will explain a little bit my implmentation. (this is typescript)

The puzzle array is an array of class

export class PuzzleNode {
goal: Node;
current: Node;

When I shuffle I don't touch the puzzleArray but I shuffle the
property like so

shuffle() {
this.prepNodes = shuffleArray(this.prepNodes);
for (let i = 0; i < this.prepNodes.length; i++) {
this.nodes[i].current = this.prepNodes[i];
/** Keep shuffling until getting a solvable puzzle */
if (!this.isSolvable()) {

This way I can reach any node using the index, because the index doesn't change even after shuffling, for instance the blank tile is always


The way to vary the difficulty would be to reduce or increase the number of moves required to solve it.

I think the best way to go about this is to implement the shuffling algorithm as a reverse of the way it will be solved: while shuffling, only pick legal moves (move a piece into an adjacent gap), and repeat this randomly for a certain number of moves until it's sufficiently shuffled.

For easy mode, only do about 5 moves. For hard, do 30 moves. A puzzle that requires 5 moves to solve will be a lot easier.