Home/ Questions/Q 8419537
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-06-10T02:38:29+00:00

Firstly, I have read every thread that I could find on stackoverflow or other

  • 0

Firstly, I have read every thread that I could find on stackoverflow or other internet searching. I did learn about different aspects, but it isn’t exactly what I need.

I need to solve a Rush Hour puzzle of size no larger than 8 X 8 tiles.

As I have stated in title I want to use A*, as a heuristic for it I was going to use :
number of cars blocking the red car’s ( the one that needs to be taken out ) path should decrease or stay the same.

I have read the BFS solution for Rush hour.

I don’t know how to start or better said, what steps to follow.

In case anyone needs any explanation, here is the link to the task :

http://www.cs.princeton.edu/courses/archive/fall04/cos402/assignments/rushhour/index.html

So far from what have I read ( especially from polygenelubricants’s answer ) I need to generate a graph of stages including initial one and “succes” one and determine the minimum path from initial to final using A* algorithm ?

Should I create a backtracking function to generate all the possible ( valid ) moves ?

As I have previously stated, I need help on outlining the steps I need to take rather than having issues with the implementation.

Edit : Do I need to generate all the possible moves so I convert them into graph nodes, isn’t that time consuming ? I need to solve a 8X8 puzzle in less than 10 seconds

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    A* is an algorithm for searching graphs. Graphs consist of nodes and edges. So we need to represent your problem as a graph.

    We can call each possible state of the puzzle a node. Two nodes have an edge between them if they can be reached from each other using exactly one move.

    Now we need a start node and an end node. Which puzzle-states would represent our start- and end-nodes?

    Finally, A* requires one more thing: an admissable distance heuristic – a guess at how many moves the puzzle will take to complete. The only restriction for this guess is that it must be less than the actual number of moves, so actually what we’re looking for is a minimum-bound. Setting the heuristic to 0 would satisfy this, but if we can come up with a better minimum-bound, the algorithm will run faster. Can you come up with a minimum-bound on the number of moves the puzzle will take to complete?

    • 0