15
votes
Accepted
Find the correct path through a 5 x 5 grid (coderbyte 'Correct path')
Unnecessary Import
numpy is not required for this challenge. You are using none of its special capabilities. The following:
...
- 35.3k
13
votes
Accepted
Python program to find a word ladder transforming "four" to "five"
By performing recursion, you are performing a depth-first search of four-letter words. However, this task involves finding a shortest path, and shortest-path problems are generally better done using ...
- 146k
12
votes
Bellman-Ford optimisation in C
for (uint _ = 0; _ < nb_nodes - 1; _++)
Maybe this was python code translated into C?!?
Repect the norms of the community.
Even though ...
- 42.2k
10
votes
Dijkstra path finding in C# is 15x slower than C++ version
More speed for both C++ and C#
Revisiting an older question. While reading this question and its already very good answers the ...
- 2,515
9
votes
Accepted
9
votes
Accepted
Implementation of A* algorithm in C++
Euclidean distance is used to calcualte the cost from current node to goal
The code implements Manhattan distance, so the comment is wrong, or perhaps the code is wrong, but in any case it doesn't ...
- 12.4k
9
votes
Optimizing Python BFS Code
I have only a couple of nitpicks:
Nitpick 1
while len(queue) > 0:
You can write just as:
while queue:
Nitpick 2
Instead of ...
- 32k
9
votes
Faux Random Maze Generator
Overview
There is a lot to like about this code:
Most of the code is well laid out, with consistent indentation and spacing.
The functions and most of the variables have meaningful names.
The ...
- 15.8k
8
votes
Accepted
A* Algorithm in C# for pathfinding 2D tile grid
There is a lot of code here, so there is a lot to say; no way I'll covered everything! I'll do the easy things first, and then assume lots of them before we look at the algorithm.
Style
Usually C#ers ...
- 7,591
8
votes
Compute shortest path in undirected graph
Intro code:
There's a lot of "instant fail"s here:
Include only the headers you need!
Debugging macros are probably not acceptable for something like this. We can step through in a ...
- 12.2k
8
votes
Faux Random Maze Generator
get_direction works too hard. Expanding on Fe2O3 suggestion, notice that dx and dy are ...
- 58.7k
8
votes
Accepted
Shortest unrestricted path to touch every square in an n by n grid
Time complexity
You have \$O(n^2)\$ start points. Each of those run a DFS. Assuming, as a lower bound, that the DFS explores every possible edge, then that's \$O(n^2)\$ steps per DFS. The actual ...
- 69.3k
7
votes
Accepted
Fastest path on a snakes and ladders board
Don't use mutable default arguments. If you need to default to a list then default to None and then change to an empty list.
Take the following example code:
<...
- 44.6k
7
votes
Implementation of Dijkstra's algorithm in Python
[x for x in range(1, 1001)] can be written as just list(range(1, 1001)).
It would be good to give that ...
- 16.6k
7
votes
Accepted
Optimizing Python BFS Code
current = queue.pop()
What this actually does, which perhaps you did not notice, is remove the last element of the list. So the queue is really a stack, and ...
- 12.4k
7
votes
Bellman-Ford optimisation in C
A few pieces of advice you can consider:
As far as I'm aware, documentation comments are conventionally immediately before the declaration, not between the signature and the body of the ...
- 1,576
7
votes
Faux Random Maze Generator
This looks good overall. I'll try not to repeat other answers, sorry if something is still duplicated.
I've got a couple of "major" notes that indeed raised my eyebrows, and then several ...
- 2,072
6
votes
Find the correct path through a 5 x 5 grid (coderbyte 'Correct path')
calcpath should be calc_path as per PEP8. This seems like it's a name decided on by the challenge, but I thought I'd mention it.
...
- 16.6k
6
votes
Accepted
Speeding up Dijkstra's algorithm
PEP-8 Violations
Variables (unseenNodes, currentNode) should be snake_case, not ...
- 35.3k
6
votes
Accepted
A* (shortest path) with the ability to remove up to one wall
The high level approach
What would be a good way of implementing the wall logic to be within the A* algorithm? I've tried to simply add a canRemove boolean to the Cell object (which is holding the ...
- 12.4k
6
votes
Accepted
Multithreading a shortest path algorithm
Avoid redefining integer types
I see types like sint and uint, I think somewhere you have lines like:
...
- 69.3k
6
votes
Computing most probable (reliable) path in a probabilistic graph (take II)
Two stylistic things jump out at me.
You use StringBuilder in the below, but elsewhere you use String.format.
...
- 4,614
5
votes
Accepted
Google FooBar "Prepare The Bunnies Escape"
SPOILER ALERT
This puzzle is a very slight modification of the well-known fuzzy string matching problem, which can be solved efficiently using (what else?) dynamic programming. Imagine you're a bunny ...
- 19.7k
5
votes
Fastest path on a snakes and ladders board
continue # Forbid a dice-roll that lands on a snake
This may prevent finding the shortest path - it's possible to imagine a board with two long ladders, ...
- 88.3k
5
votes
Implementation of A* algorithm in C++
Just off the cuff, before I fully code review this, I would tell you:
1) There are not enough comments. You add comments like this:
...
- 106
5
votes
Accepted
C#: A* pathfinding - performance and simplicity
Boxing from value PathNode to reference IPathNode causes another half of allocations. But making ...
- 12.4k
5
votes
Accepted
Python: Astar algorithm implementation
self.start, self.grid, self.height, self.width = start, grid, height, width
I would not put these all on the same line like that. I think it would be much easier ...
- 16.6k
5
votes
Compute shortest path in undirected graph
In addition to user673679 and Toby Speight's answers, here are a few more issues:
Use a consistent code style
Sometimes I see spaces around commas, sometimes not, the body of ...
- 69.3k
5
votes
Accepted
Searching for a performance bug in a C++20 pathfinding algorithm (NBA*)
Avoid manual new and delete
I see a lot of new and delete...
- 69.3k
Only top scored, non community-wiki answers of a minimum length are eligible