Import java.util.
Scanner;
Public class DistanceVectorRouting {
Private static final int INF = 999; // Infinity, used for unreachable nodes
Private int numNodes;
Private int[][] distanceMatrix;
Private int[][] routingTable;
// Constructor to initialize the network
Public DistanceVectorRouting(int numNodes) {
This.numNodes = numNodes;
This.distanceMatrix = new int[numNodes][numNodes];
This.routingTable = new int[numNodes][numNodes];
}
// Function to initialize the distance matrix and routing table
Public void initialize(Scanner sc) {
System.out.println(“Enter the distance matrix (Enter 999 for no direct
connection):”);
For (int I = 0; I < numNodes; i++) {
For (int j = 0; j < numNodes; j++) {
distanceMatrix[i][j] = sc.nextInt();
// Initialize routing table to distance matrix values
routingTable[i][j] = distanceMatrix[i][j];
}
}
}
// Function to perform the distance vector algorithm
Public void distanceVectorAlgorithm() {
For (int k = 0; k < numNodes; k++) { // Repeat for convergence
For (int I = 0; I < numNodes; i++) {
For (int j = 0; j < numNodes; j++) {
// Update routing table if a shorter path is found through node k
If (routingTable[i][j] > routingTable[i][k] + routingTable[k][j]) {
routingTable[i][j] = routingTable[i][k] + routingTable[k][j];
}
}
}
}
}
// Function to display the routing tables
Public void displayRoutingTables() {
For (int I = 0; I < numNodes; i++) {
System.out.println(“\nRouting table for Node “ + (I + 1) + “:”);
For (int j = 0; j < numNodes; j++) {
If (routingTable[i][j] == INF) {
System.out.print(“INF\t”);
} else {
System.out.print(routingTable[i][j] + “\t”);
}
}
System.out.println();
}
}
Public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
// Input number of nodes
System.out.print(“Enter the number of nodes: “);
Int numNodes = sc.nextInt();
DistanceVectorRouting dvr = new DistanceVectorRouting(numNodes);
Dvr.initialize(sc); // Initialize the network
Dvr.distanceVectorAlgorithm(); // Perform the Distance Vector algorithm
Dvr.displayRoutingTables(); // Display the updated routing tables
Sc.close();
}
}
