Python Coding challenge - Day 406| What is the output of the following Python Code?

 

Code Explanation:

Importing NetworkX

import networkx as nx  

Imports the networkx library, which is used for graph creation and analysis in Python.

Creating a Directed Graph

G = nx.DiGraph([(1, 2), (2, 3), (3, 1), (3, 4)])  

Creates a directed graph (DiGraph).

Adds four directed edges:

1 → 2

2 → 3

3 → 1

3 → 4

Graph Representation:

   1 → 2  

   ↑    ↓  

   3 ←  4  

Finding Predecessors of Node 3

pred = list(G.predecessors(3))  

Finds all nodes that have an edge pointing to 3 (predecessors).

In the graph:

2 → 3 (So 2 is a predecessor)

1 → 3 (So 1 is a predecessor)

Output:

[2, 1]

Finding Successors of Node 3

succ = list(G.successors(3))  

Finds all nodes where 3 points to (successors).

In the graph:

3 → 1

3 → 4

Output:

[4]

Printing Predecessors and Successors

print(pred, succ)  

Prints the predecessors and successors of node 3.

Final Output:

[2] [1,4]

[][2] [1, 4][2] [1, 4]