Given two integers V and E which represent the number of Vertices and Edges of a Planar Graph. The Task is to find the number of regions of that planar graph.
Planar Graph: A planar graph is one in which no edges cross each other or a graph that can be drawn on a plane without edges crossing is called planar graph.
Region: When a planar graph is drawn without edges crossing, the edges and vertices of the graph divide the plane into regions..
Input: V = 4, E = 5
Output: R = 3
Input: V = 3, E = 3
Output: R = 2
Approach: Euler found out the number of regions in a planar graph as a function of the number of vertices and number of edges in the graph i.e.
Below is the implementation of the above approach:
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