Each map can be represented by a graph. Each region of the map is represented by a vertex. Edges connect two vertices if the regions represented by these vertices have a common border.
Input: graph G (V, E). Output: Colored Graph with the number of colors. Step 1: Assign an order to the set of colors. Step 2: Considering the first vertex in the vertex order, assign to it the first color. Step 3: Considering the next vertex, assign to it the lowest-ordered color that has not already been assigned to a vertex adjacent to it. Step 4: Repeat step 3 until the graph is colored.
