Solving the region-coloring problem

Let's use the Constraint Satisfaction framework to solve the region-coloring problem. Consider the following screenshot:

We have a few regions in the preceding figure that are labeled with names. Our goal is to color with four colors so that no adjacent regions have the same color.

Create a new Python file and import the following packages:

from simpleai.search import CspProblem, backtrack 

Define the constraint that specifies that the values should be different:

# Define the function that imposes the constraint  
# that neighbors should be different 
def constraint_func(names, values): 
    return values[0] != values[1]   

Define the main function and specify the list of names:

if __name__=='__main__':
    # Specify the variables
    names = ('Mark', 'Julia', 'Steve', 'Amanda', 'Brian', 
            'Joanne', 'Derek', 'Allan', 'Michelle', 'Kelly')

Define the list of possible colors:

    # Define the possible colors...