In this way, the map coloring problem becomes a graph coloring problem: Color the vertices so neighbors are different colors. The minimum number of colors is called the chromatic number of the graph.

Graph coloring problems tend to be simple to state, but they are often enormously hard to solve. Even the question that launched the field — Do four colors suffice to color any map? — took more than a ...

Color plays an important role in how people ... Media consumers are inundated with facts, charts, graphs and maps every day. If you can take a moment to ask yourself a few questions about what ...