PageRank.java

packagecom.thealgorithms.others;

importjava.util.Scanner;

classPageRank {

publicstaticvoidmain(String[] args) {
intnodes;
inti;
intj;
Scannerin = newScanner(System.in);
System.out.print("Enter the Number of WebPages: ");
nodes = in.nextInt();
PageRankp = newPageRank();
System.out.println("Enter the Adjacency Matrix with 1->PATH & 0->NO PATH Between two WebPages: ");
for (i = 1; i <= nodes; i++) {
for (j = 1; j <= nodes; j++) {
p.path[i][j] = in.nextInt();
if (j == i) {
p.path[i][j] = 0;
 }
 }
 }
p.calc(nodes);
 }

publicint[][] path = newint[10][10];
publicdouble[] pagerank = newdouble[10];

publicvoidcalc(doubletotalNodes) {
doubleinitialPageRank;
doubleoutgoingLinks = 0;
doubledampingFactor = 0.85;
double[] tempPageRank = newdouble[10];
intexternalNodeNumber;
intinternalNodeNumber;
intk = 1; // For Traversing
intiterationStep = 1;
initialPageRank = 1 / totalNodes;
System.out.printf(" Total Number of Nodes :" + totalNodes + "\t Initial PageRank of All Nodes :" + initialPageRank + "\n");

// 0th ITERATION _ OR _ INITIALIZATION PHASE //
for (k = 1; k <= totalNodes; k++) {
this.pagerank[k] = initialPageRank;
 }
System.out.print("\n Initial PageRank Values , 0th Step \n");

for (k = 1; k <= totalNodes; k++) {
System.out.printf(" Page Rank of " + k + " is :\t" + this.pagerank[k] + "\n");
 }

while (iterationStep <= 2) { // Iterations
// Store the PageRank for All Nodes in Temporary Array
for (k = 1; k <= totalNodes; k++) {
tempPageRank[k] = this.pagerank[k];
this.pagerank[k] = 0;
 }

for (internalNodeNumber = 1; internalNodeNumber <= totalNodes; internalNodeNumber++) {
for (externalNodeNumber = 1; externalNodeNumber <= totalNodes; externalNodeNumber++) {
if (this.path[externalNodeNumber][internalNodeNumber] == 1) {
k = 1;
outgoingLinks = 0; // Count the Number of Outgoing Links for each externalNodeNumber
while (k <= totalNodes) {
if (this.path[externalNodeNumber][k] == 1) {
outgoingLinks = outgoingLinks + 1; // Counter for Outgoing Links
 }
k = k + 1;
 }
// Calculate PageRank
this.pagerank[internalNodeNumber] += tempPageRank[externalNodeNumber] * (1 / outgoingLinks);
 }
 }
System.out.printf("\n After " + iterationStep + "th Step \n");

for (k = 1; k <= totalNodes; k++) {
System.out.printf(" Page Rank of " + k + " is :\t" + this.pagerank[k] + "\n");
 }

iterationStep = iterationStep + 1;
 }

// Add the Damping Factor to PageRank
for (k = 1; k <= totalNodes; k++) {
this.pagerank[k] = (1 - dampingFactor) + dampingFactor * this.pagerank[k];
 }

// Display PageRank
System.out.print("\n Final Page Rank : \n");
for (k = 1; k <= totalNodes; k++) {
System.out.printf(" Page Rank of " + k + " is :\t" + this.pagerank[k] + "\n");
 }
 }
 }
}