Challenge 5: Count the Number of Edges in an Undirected Graph

Problem statement

You have to implement the int numEdges(Graph g) function, which takes an undirected graph and computes the total number of bidirectional edges. An illustration is also provided for your understanding.

Input

The input is an undirected graph.

Output

It returns the total number of edges in the graph.

Sample input

graph = {
    0 - 2
    0 - 5
    2 - 3
    2 - 4
    5 - 3
    5 - 6
    3 - 6
    6 - 7
    6 - 8
    6 - 4
    7 - 8
}

Sample output

11