Markov Blanket Size

Problem

The Markov blanket of a node in a Bayesian network consists of its parents, its children, and the other parents of its children. Given directed edges as [parent, child] pairs and a node index, return the number of distinct nodes in its Markov blanket. Return 0 for malformed edges.

Hint

Union the parents, the children, and everyone who shares a child with the node.

Test cases

case 1

in: [[[0,1],[2,1],[1,3]],1]

expected: 3

case 2

in: [[[0,1],[2,1],[1,3]],0]

expected: 2

case 3

in: [[[0,1],[0,2]],0]

expected: 2

case 4

in: [[[1,2],[3,2],[1,4],[3,4]],1]

expected: 3

case 5

in: [[],0]

expected: 0

Starter codePython

def markov_blanket_size(edges, node):
    # Your code here
    pass

5 test cases · run your code against them in the editor