In algorithms, as in life, negativity can be a drag. Consider the problem of finding the shortest path between two points on a graph — a network of nodes connected by links, or edges. Often, these ...

* Why do you want to base this on Dijkstra's algorithm, which is designed to find a single shortest-path? Surely there are better options for your base implementation. A quick Google search suggests a ...

What is a Breadth-first search? If you have a tree structure as below and visit the root node, and then all of its children, and all of its children’s children, and so on, that’s a so-called ...

Here is a problem I'm working on. Say you have a weighted, directed graph with n vertices and m edges, and you want to find the shortest path from s to all other vertices, *but* you can only use some ...

The original version of this story appeared in Quanta Magazine. If you want to solve a tricky problem, it often helps to get organized. You might, for example, break the problem into pieces and tackle ...