justcoding121 / advanced-algorithms Goto Github PK

if (current.Point.X == point.X && current.Point.Y == point.Y) return current;

Hi,

would it be possible for Clone() method on graphs to be public? Is there any reason why it's not at the moment?
For example I want to build one part of the graph (because it's static for my problem), but later I'd like to add some edges. I don't want to modify the static part of the graph because I will need it once more. Now I'm forced to Clone it myself and I don't even know how to do it, because I don't see any way of enumerating the vertices atm (only enumerating the vertex values).

Firstly, massive and heartfelt thanks for this great selection of algorithms I need to write my project. Been trying them out - saved me weeks of coding and testing.

For this (and the Dijkstra and possibly others) VS can't seem to locate the classes inherited from the abstract IShortestPathOperators in any of the using directives. I've tried quite a few. Not a massive problem as I copied the FloydWarshallShortestPathOperators class into my project from your online source code and all works well, but I figure you intended that they should be automatically available somewhere.

Anyway, thanks again, these are fantastic!

Any plans for targeting .NetStandard 1/2 and releasing all this great work as a NuGet package?

Thanks for this library! It is the best I have found on C# for this. I'd suggest you add some C# documentation on your main calls. Although comments usually are a bad practice, for libraries they really help to understand the calls.
For example, by reading the code I could understand what the combination class does, but by reading the method name itself, I couldn't. It would be nice to provide at least a simple example of input/output. Nothing more.

The following graph is considered as not bipartite by the algorithm (which in reality is):
(0) -- (2)
(1) -- (3)

as in MColorer appears to be unable to color the disconnected graph using 2 colors.

https://github.com/justcoding121/Advanced-Algorithms/blob/0e1b90aaf322104ec9bdf7e5b4ab55a39e920aed/tests/Advanced.Algorithms.Tests/Graph/Matching/BiPartiteMatching_Tests.cs#L40

Given a simple fully connected bipartite graph K_{3,3} the maximum matching algorithm crashes with an error:
assuming U={A, B, C} and V={D, E, F}
the exception is raised in the following line:

https://github.com/justcoding121/Advanced-Algorithms/blob/0e1b90aaf322104ec9bdf7e5b4ab55a39e920aed/src/Advanced.Algorithms/Graph/Matching/HopcroftKarp.cs#L57

System.ArgumentException: 'An item with the same key has already been added. Key: E'

Since rightMatch dictionary already contains a mapping between E and A the algorithm cannot add a mapping between E and C on top of it

Hi, I need to perform Tarjan strongly components finding algorithm on a weighted directed graph. Is there any way to do that, except for manually trying to convert one graph to another? Thanks.

Bentley-Ottman algorithm throws NullReferenceException with certain input.
Example input:
Line 1: 100, 0; 150, 130
Line 2: 20, 80; 80, 70
Line 3: 80, 70; 50, 100

Hi,

BloomFilter uses GetHashCode, which yields for strings no deterministic value.
This means every test returns true.

     Advanced.Algorithms.DataStructures.BloomFilter<string> bloomFilter = new Advanced.Algorithms.DataStructures.BloomFilter<string>(10);
            bloomFilter.AddKey("foo");
            bloomFilter.AddKey("bar");
            bloomFilter.AddKey("apple");
            bloomFilter.AddKey("orange");
            bloomFilter.AddKey("banana");

            bloomFilter.KeyExists("bar").ShouldBe(true);
            bloomFilter.KeyExists("ba111r").ShouldBe(true); // is true
            bloomFilter.KeyExists("banana").ShouldBe(true);
            bloomFilter.KeyExists("dfs11j").ShouldBe(false);`// is also true

https://en.wikipedia.org/wiki/Edmonds%27_algorithm implementation is missing. It would be great to have it altogether with other graph-related stuff.

Hi, the Bentley-Ottmann algorithm implementation seems to fail to detect all intersection points.

var lines = new List<Line>()
{
    new Line(new Point(0.307769600445297, 0.496908523373729), new Point(0.752325133305194, 0.247345594804429)),
    new Line(new Point(0.59643911784349, 0.212231021938953), new Point(0.936056684207198, 0.558365820701404)),
    new Line(new Point(0.362570754886871, 0.145859633640321), new Point(0.837961102294718, 0.571770970510212)),
    new Line(new Point(0.415960443865489, 0.216604132306112), new Point(0.746803699409032, 0.5559045125525)),
};
BentleyOttmann bentleyOttmann = new BentleyOttmann(7);
var count = bentleyOttmann.FindIntersections(lines).Count;
Console.WriteLine(count); // only 2 instead of 3

tracePath method implementation not working for all Nullible types. While loop:

while (!currentV.Equals(default(T)) && !parentMap[currentV].Equals(default(T)))

Will throw null reference exception on null.equals(null)