The theory of coloring deals with the problem of labeling parts of a graph to comply with certain rules and avoid specific conflicts. For example, imagine you wanted to color each dot below so that ...

The vertex cover problem seeks a minimum-cardinality set of vertices in a graph such that every edge is incident to at least one selected vertex. As an NP-hard combinatorial optimisation challenge, it ...

Have you ever tried to do the brainteaser below, where you have to connect the dots to make the outline of a house in one continuous stroke without going back over your lines? Or perhaps you've ...