1. Please implement in JAVA
c) Programming Assignment write a program to determine the connected components in the
graph shown on page 591 in the textbook. In case of multiple links between two nodes in the
same direction, you can replace them with a single link.
Solution
Program: DiGraph.java
import java.io.*;
import java.util.*;
public class DiGraph
{
private int V;
private int  count;
private int[]Â Â low;
private boolean[] visited;
private List<Integer>[] graph;
private List<List<Integer>> scc;
private Stack<Integer>Â Â Â Â Â stack;
public List<List<Integer>> getSCC(List<Integer>[] graph) // function to get all strongly
connected components
{
V = graph.length;
this.graph = graph;
low = new int[V];
visited = new boolean[V];
stack = new Stack<Integer>();
scc = new ArrayList();
for (int v = 0; v < V; v++)
if (!visited[v]) dfs(v);
return scc;
}
public void dfs(int v) //function to get depth first search

2. {
low[v] = count++;
visited[v] = true;
stack.push(v);
int min = low[v];
for (int w : graph[v])
{
if (!visited[w]) dfs(w);
if (low[w] < min) min = low[w];
}
if (min < low[v])
{
low[v] = min;
return;
}
List<Integer> component = new ArrayList<Integer>();
int w;
do
{
w = stack.pop();
component.add(w);
low[w] = V;
}while (w != v);
scc.add(component);
}
public static void main(String[] args)
{
Scanner scan = new Scanner(System.in);
System.out.println("Enter number of Vertices");
int V = scan.nextInt(); // number of vertices
List<Integer>[] g = new List[V]; //graph
for (int i = 0; i < V; i++)
g[i] = new ArrayList<Integer>();
System.out.println("Enter number of edges"); //edges
int E = scan.nextInt();
System.out.println("Enter the edges in the graph : <from> <to>"); // Each edge
for (int i = 0; i < E; i++)
{
int x = scan.nextInt();
int y = scan.nextInt();
g[x].add(y);
}
DiGraph d = new DiGraph();
List<List<Integer>> SCC = d.getSCC(g);
System.out.println(SCC); //print all strongly connected components
scan.close();

3. }
}