How to Generate a Random Undirected Graph for a Given Number of Edges in Java?

An undirected graph is graph, i.e, a set of objects (called vertices or nodes) that are connected together, where all the edges are bidirectional. An undirected graph is sometimes called an undirected network. In contrast, a graph where the edges point in a direction is called a directed graph.

Undirected Graph : Bidirectional

Examples:

Input:
Enter the number of Edges :
5
Output:
The Generated Random Graph is :
1 -> { 5 2  }
2 -> { 1  }
3 -> { Isolated Vertex! }      
4 -> { 6  }
5 -> { 1  }
6 -> { 4 10  }
7 -> { Isolated Vertex! }      
8 -> { 10  }
9 -> { Isolated Vertex! }      
10 -> { 8 6  }

Input:
Enter the number of Edges :
10
Output:
The Generated Random Graph is :
1 -> { 4 9  }
2 -> { 8  }
3 -> { 8  }
4 -> { 1 6  }
5 -> { 6  }
6 -> { 10 5 8 9 4  }
7 -> { 8  }
8 -> { 7 3 6 2  }
9 -> { 1 6  }
10 -> { 6  }

Approach:

• Take the input of the number of edges for the random Directed Acyclic Graph.
• Build a connection between two random vertices iteratively.
• Assert “Isolated Vertex” if degree of a certain vertex is zero.

Implementation:

Enter the number of Edges : 6
The Generated Random Graph is :
1 -> { 8  }
2 -> { 2  }
3 -> { Isolated Vertex! }
4 -> { 5  }
5 -> { 4 6  }
6 -> { 5  }
7 -> { 9  }
8 -> { 1 10  }
9 -> { 7  }
10 -> { 8  }