Posted on by Kalkicode
Code Graph

Find indegree and outdegree of a directed graph in node js

Js program for Find indegree and outdegree of a directed graph. Here problem description and other solutions.

/*
    Node JS Program for 
    Show degree of vertex in directed graph
*/
class AjlistNode
{
	constructor(id)
	{
		// Set value of node key
		this.id = id;
		this.next = null;
	}
}
class Vertices
{
	constructor(data)
	{
		this.data = data;
		this.next = null;
		this.last = null;
	}
}
class Graph
{
	constructor(size)
	{
		// Set value
		this.size = size;
		this.node = Array(size).fill(null);
		this.setData();
	}
	// Set initial node value
	setData()
	{
		if (this.size <= 0)
		{
			console.log("\nEmpty Graph");
		}
		else
		{
			for (var index = 0; index < this.size; index++)
			{
				// Set initial node value
				this.node[index] = new Vertices(index);
			}
		}
	}
	//  Handling the request of adding new edge
	addEdge(start, last)
	{
		if (start >= 0 && start < this.size && 
            last >= 0 && last < this.size)
		{
			// Safe connection
			var edge = new AjlistNode(last);
			if (this.node[start].next == null)
			{
				this.node[start].next = edge;
			}
			else
			{
				// Add edge at the end
				this.node[start].last.next = edge;
			}
			// Get last edge 
			this.node[start].last = edge;
		}
		else
		{
			// When invalid nodes
			console.log("\nHere Something Wrong");
		}
	}
	printGraph()
	{
		if (this.size > 0)
		{
			// Print graph ajlist Node value
			for (var index = 0; index < this.size; ++index)
			{
				process.stdout.write("\nAdjacency list of vertex " + 
                                     index + " : ");
				var temp = this.node[index].next;
				while (temp != null)
				{
					// Display graph node 
					process.stdout.write(" " + this.node[temp.id].data);
					// Visit to next edge
					temp = temp.next;
				}
			}
		}
	}
	// Find indegree and outdegree of 
	// each nodes of a given graph
	findDegree(indegree, outdegree)
	{
		var temp = null;
		var length = 0;
		for (var i = 0; i < this.size; ++i)
		{
			temp = this.node[i].next;
			length = 0;
			while (temp != null)
			{
				// Update indegree
				indegree[temp.id]++;
				temp = temp.next;
				length++;
			}
			// Set outdegree value
			outdegree[i] = length;
		}
	}
	showDegree()
	{
		if (this.node != null)
		{
			var indegree = Array(this.size).fill(0);
			var outdegree = Array(this.size).fill(0);
			// Set zero degree
			for (var i = 0; i < this.size; i++)
			{
				indegree[i] = 0;
				outdegree[i] = 0;
			}
			// Find degree
			this.findDegree(indegree, outdegree);
			console.log("\n");
			// Display result
			for (var i = 0; i < this.size; ++i)
			{
				console.log("Node [" + i + 
                            "] indegree [" + indegree[i] + 
                            "] outdegree [" + outdegree[i] + "]");
			}
		}
		else
		{
			process.stdout.write("Empty Graph");
		}
	}
}

function main()
{
	// 6 implies the number of nodes in graph
	var g = new Graph(6);
	// Connected two node with Edges
	g.addEdge(0, 1);
	g.addEdge(0, 2);
	g.addEdge(0, 5);
	g.addEdge(2, 3);
	g.addEdge(3, 1);
	g.addEdge(4, 0);
	g.addEdge(4, 1);
	g.addEdge(5, 0);
	g.addEdge(5, 2);
	g.printGraph();
	// Test
	g.showDegree();
}
// Start program execution
main();

Output

Adjacency list of vertex 0 :  1 2 5
Adjacency list of vertex 1 :
Adjacency list of vertex 2 :  3
Adjacency list of vertex 3 :  1
Adjacency list of vertex 4 :  0 1
Adjacency list of vertex 5 :  0 2

Node [0] indegree [2] outdegree [3]
Node [1] indegree [3] outdegree [0]
Node [2] indegree [2] outdegree [1]
Node [3] indegree [1] outdegree [1]
Node [4] indegree [0] outdegree [2]
Node [5] indegree [1] outdegree [2]

Comment

Please share your knowledge to improve code and content standard. Also submit your doubts, and test case. We improve by your feedback. We will try to resolve your query as soon as possible.

New Comment