# Questions tagged [a-star]

A* is a graph shortest-path algorithm that uses a heuristic function to speed up the search

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7k views

### A* pathfinding algorithm too slow

I'm trying to make a pathfinding algorithm for my project. I need it for a simulation and I need it to be fast!!! I watched a few videos explaining the algorithm online and came up with the code ...
4k views

### Optimizing an A* algorithm

I am currently using an implementation of the A* algorithm described here. Currently, when I run my algorithm, my IDE lags horribly and the .exe generated also lags terribly. Using the CPU analyzer, ...
8k views

### Solving 15 puzzle

I'm trying to solve 15 puzzle using A* algorithm, but something really bad goes on in my get_solution() function that ruins performance. I guess there is a too much ...
2k views

### A* search in MATLAB

I have implemented A* search in MATLAB, but I am looking for ways to increase the speed and optimize it. I have tried using a priority queue but I found it doesn't work that well, so I am using a ...
365 views

### A* Go application

I've written a generic implementation of the A* algorithm as a first Go program, since I had implemented that both in C and in Python before and Go reminds me a bit of both. I'm looking for general ...
161 views

### Game of 15 - A* search

I would be really thankful for review of this homework. I'm trying to write better code in terms of readability and design patterns. This program solves the classic 15 slider puzzle with A* search. ...
319 views

### Typesetting A* in LaTeX using algorithm2e

(See the next iteration.) The result looks like and my code is: ...
3k views

### Implementation of A* algorithm in C++

I have implemented the A-Star path finding algorithm for a 2D grid. The function returns a list of positions of an acceptable path. main.cpp : ...
7k views

### 8puzzle solver using A*

That's gonna take long. This program solves 8 puzzle game (mini version of 15 puzzle) using A* algorithm. Program consists of 2 parts: Board.java - which serves ...
620 views

### Shortest path to transform one word into another

I submitted the following code for a job application, and was rejected. They gave no feedback. Would appreciate any comments on the approach I took, and coding style. This is the question: Given ...
936 views

### Moving game objects along an A* Path

I am having a game with a lot of GameBodyObjects and some of them are moving, some of them are not. When I calculate A* for the moving objects it gets really slow ...
134 views

### Algorithm to find a path

I have implemented A* in C, and was wondering about what I could do to improve it. My main concerns are readability, usability and last but not least performance. My NodeList is an attempt at making ...
365 views

### A* Algorithm in F#

Inspired by this post I looked up A* on wikipedia and went on with my own implementation as seen below where I try to mimic the pseudocode on Wikipedia but in a recursive manner. I would like any ...
139 views

### Python: Astar algorithm implementation

I have implemented Astar algorithm for a problem on an online judge relating to maze given start and end positions along with a grid representing the maze. I output the length of the path along with ...
313 views

### A* algorithm in C# for use in a game

I recently started up again on a 2D game engine I have been working on over the last couple of years. I managed to implement a version of the a* algorithm that seems to work fine for my game, but it ...
412 views

### A* Generic Implementation in Swift

My first Code Review post. I'm up to a generic implementation of the A* search algorithm in Swift (for now, it's a single goal implementation). Here's what's been coded so far: ...
2k views

### My 15 puzzle solver is too slow

It takes my code over 700 seconds to solve simple puzzle: 2 7 11 5 13 0 9 4 14 1 8 6 10 3 12 15 My function ...
2k views

### A* search algorithm: open set and heap

I'm working on an A* search algorithm implemention and this is what I came up with for the open list: ...
179 views

### Latitude/Longitude graph optimised A* Algorithm

Can anyone point me in the direction of a C# or pseudocode implementation of A* optimised for relatively sparsely connected graphs (average < 3 edges per node)? ...
201 views

### A* in Clojure - trickier than I expected

While working through some coding puzzles to brush up on Clojure, I encountered the need to use A* on some search problems. I tried to implement it from first principles/memory and that didn't go ...
140 views

### A* implementation is not running efficiently but gets correct result

I'm not entirely sure what code other people will need to see, if I miss something off that is important please leave me a comment and I will update it as soon as I possibly can. I have coded an A* ...
2k views

### C++ implementation of the A* pathfinding algorithm

A lot of the code I show here is simply setting the environment and doesn't really affect the algorithm itself, so please don't get scared away by the amount of code. The algorithm itself is showed at ...
4k views

### A* (A-Star) pathfinding algorithm with dynamic node generation in Python

I wrote code which implements the A* algorithm in Python. A* is a shortest path algorithm which resembles Dijkstra's Algorithm, but includes an estimator to guide the search. The pseudocode of both ...
72 views

### Performance Enhancement of A Star Path Finder algorithm with 1024 multidimentional array

I have the below code for a A* pathfinder, however it is taking upwards of 10 minutes to find a solution using a simple 1024 x 1024 array. I had to comment out ...
1k views

### A* implementation

I wrote a little A* implementation by my own and would like to have some feedback ;) The code is in OOP way, thus we can use an other pathfinding algorithm easily. The "Base" is just the interface ...
47 views

### A* and ALT pathfinding in C tips

I adding some pathfinding to a game I'm working on. It primarily used A* with as suggested in the pathfinding articles at reb blob games. It works, but isn't very fast. It is a square grid map that (...
508 views

### A* algorithm as simple as possible

I'm a beginner when it comes to path finding, so I decided to write an as simple as possible (to me) A* algorithm to learn. I looked up on internet the general idea and found some pseudo-code that I ...
760 views

### Find shortest path using A*

I have this c++ program. It is about A* algorithm, but the way it is written, its very hard to be understood and very hard to read. How would you edit the code so it is more correct grammatically and ...
79 views

### A* pathfinding for integer Vectors

This class is for calculating the shortest path in a 2D World (without minding obstacles). I'm using the A* algorithm and 2D Vectors (from the SFML Framework). It is working but takes (a lot of) time ...
203 views

### A-Star Search with 3D Universe

I am attempting to write up a program in Python that will find the shortest path between two nodes in 3D space. The actual domain is the EVE-Online Universe, which is composed of systems connected by ...
4k views

### New way of doing the A* Algorithm

I wrote a Python script for implementing an A* algorithm. Map, Start and Goal are given. The code works well as far as I tested it but I want to get feedback from the best out there too. So I am ...
1k views

### Python: AStar Pathfinder algorithm

Traverse through any binary array using the Manhattan distance by giving a start node location and an end node location. The neighbor() method gives the neighbors next to the x,y coordinates that are =...
1k views

### Slow 8/15-puzzle IDA*

I am trying to find the optimal solution for a given 15-puzzle. So far as I can tell, the algorithm works (on simple instances of 8-puzzle), but is extremely slow for complex starting states (order of ...
753 views

### Using the A* algorithm to search a graph generated from a grid

Following on from my previous question, I finally got round to actually doing the A* search for the Graph<MapTile>. The changes to the code from the previous ...
53 views

### I wrote my first pathfinding algorithm

I'm currently writing a small game in Lua, using the Love2d framework. I guess I'm doing it as a practice of sorts, but it did give me the opportunity to write my first pathfinding algorithm. I wrote ...
177 views

### A* algorithm optimization and implementation

I am implementing the A* algorithm in Python and have successfully completed the task. It works and even spits out the coordinates from the start to the end. However, I am programming a bot for a ...
389 views

### Npuzzle solver using A* with Manhattan + Linear Conflict (Updated Code)

Here is the old thread that I started out with. The code I've got now is vastly different thanks to those two. What I have now functions fairly well and looks pretty good. I've managed to work it back ...
1k views

### N-puzzle solver using A* with Manhattan + Linear Conflict

I've been working on this solution for a couple days now. Finally managed to get it to work and I got it to where it solves about half of the time. The other half goes for so long that it eventually ...
509 views

### A* Pathfinding for a Game

I'm working on a game and I have developed A* path finding for certain enemies. But I think I have some optimization issues. If I put the player in an area that cannot be reached and put 3 or 4 ...
154 views

### A* search on 4x4 sliding tile puzzle scales poorly

I am trying to improve the time complexity of my A* search algorithm and I have tried approaching this from every which way I believe is possible. I believe I may be doing something fundamentally ...
706 views

### N-puzzle solver using A* search

I have written a Java program to solve a N-puzzle with A* search and manhattan distance. My program can solve every 8-puzzle I have tested under 1 second, but it can't solve a 15-puzzle after 30 ...
285 views

### C++ - Astar search algorithm using user defined class

The objective of the post is to improve design and improve command on C++. Given a map, start point and end point, the shortest path to end point from the start point has to be found out using Astar (...
657 views

### C# A* Pathfinding implementation, focusing on reusability and efficiency

I wrote a C# A* pathfinding (Though, it's generic enough that it could be used for other search purposes) implementation. I started this when I found that existing implementations often didn't support ...
170 views

### Typesetting A* in LaTeX using algorithm2e - follow-up

(See the previous and initial iteration.) I have this second version of my LaTeX code. I made it less dry by removing the duplicate keyword definitions shared by the two algorithms being typeset. ...
256 views

### C++ 8-Sliding Puzzle Solver is very slow

I have made a sliding puzzle solver which is currently for 8-puzzles only. It works too slowly even though it is based on an A* algorithm whose f-score is calculated on the basis of Manhattan Distance ...
187 views

### F# implementation of the A* algorithm

This is my first attempt at writing something useful in F# and in a functional way in general. I would appreciate if you could point out any issue, even details, as I'd like to put all the bad habits ...
258 views

### Optimisation of A* in C++

I'm working on an A* pathfinding algorithm to solve a programming problem, and part of the constraint is the runtime. I need to find a path in a 2D grid with blocked or non-blocked tiles. You can't ...
555 views

### A* Search with Array Lists

I implemented A* Search with Array Lists following the pseudocode here. I have been working with different algorithms on my own, and now, I am trying to optimize them so that I can run them with less ...
10k views

### 8-Puzzle using A* and Manhattan Distance

I have developed this 8-puzzle solver using A* with manhattan distance. Appreciate if you can help/guide me regarding: 1. Improving the readability and optimization of the code. 2. I am using sort to ...
194 views

### Python A Star with fewest turns and shortest path variations

I had a lot of fun writing these. I haven't seen a version minimizing turns, so that was a neat challenge. Any suggestions are very welcome. Is there anything to gain by making more method variables ...