Discussion

IBM ILOG Solver User's Manual > The Basics > Modeling and Solving a Simple Problem: Map Coloring > Describe > Discussion

Discussion

INDEX

What is known?

You have six known countries on a map.
You have four known colors.

What is unknown?

The unknown is the connection between the country and the color: what color is each country? In other words, there are six variables; each variable represents the color of a specific country on the map. Each decision variable has four possible values: blue, white, yellow, or green.

What are the constraints?

In this case, each constraint is that a country cannot be the same color as its neighbors. In other words, if the value of the variable representing the color of Belgium is blue, then the value of the variable representing the color of Germany cannot also be blue, since they are neighboring countries.

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