Challenge 8: Find the Shortest Path Between Two Vertices

Problem statement

Implement the int findMin(Graph g, int source, int destination) function, which will take a graph and two vertices: source and destination. The result will be the shortest path from source to destination.

Remember that the shortest path will contain the minimum number of edges.

Note: The shortest distance between the same source and destination vertex will be 0.

Note: Your program should return -1 if either source or destination node do not exist.

Input

This is a directed graph, a source vertex, and a destination vertex.

Output

It returns the number of edges in the shortest path between source and destination.

Sample input

graph = {
    0 - 1
    0 - 2
    0 - 3
    3 - 5
    5 - 4
    2 - 4
}

source = 0 
destination = 4

Sample output

2