Improving A* for memory – IDA*

IDA* is a variant of an algorithm called Iterative Deepening Depth-First Search. Its memory usage is lower than A* because it doesn't make use of data structures to store the looked-up and explored nodes.

Getting ready

For this recipe, it is important to have some understanding of how recursion works.

How to do it...

This is a long recipe that can be regarded as a big two-step process: creating the main function and an internal recursive one. Please take into consideration the comments in the code for better understanding of the implementation and code flow:

1. Let's start by defining the main function, GetPathIDAstar:

public List<Vertex> GetPathIDAstar(GameObject srcObj, GameObject dstObj, Heuristic h = null) 
{ 
    if (srcObj == null || dstObj == null) 
        return new List<Vertex>(); 
    if (ReferenceEquals(h, null)) 
        h = EuclidDist; 
    // next steps; 
} 

2. Declare and compute the variables to use alongside the algorithm:

List<Vertex&gt...