While perhaps not quite as popular as A* Pathfinding (which we will cover next), it's crucial to understand Dijkstra's algorithm, as it lays the foundation for other similar approaches to finding the shortest path between two nodes in a graph. The algorithm was published by Edsger W. Dijkstra in 1959. Dijkstra was a computer scientist, and though he may be best known for his namesake algorithm, he also had a hand in developing other important computing concepts, such as the semaphore. It might be fair to say Dijkstra probably didn't have StarCraft in mind when developing his algorithm, but the concepts translate beautifully to game AI programming and remain relevant to this day.
So what does the algorithm actually do? ...
