Add Page Rank (TheAlgorithms#2614)

dilroseR · web-flow · commit 2eb6d5c1413f · 2021-10-22T07:23:21.000+03:00
diff --git a/Others/PageRank.java b/Others/PageRank.java
@@ -0,0 +1,94 @@
+package Others;
+
+import java.util.*;
+
+class PageRank {
+  public static void main(String args[]) {
+    int nodes, i, j;
+    Scanner in = new Scanner(System.in);
+    System.out.print("Enter the Number of WebPages: ");
+    nodes = in.nextInt();
+    PageRank p = new PageRank();
+    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);
+  }
+
+  public int path[][] = new int[10][10];
+  public double pagerank[] = new double[10];
+
+  public void calc(double totalNodes) {
+
+    double InitialPageRank;
+    double OutgoingLinks = 0;
+    double DampingFactor = 0.85;
+    double TempPageRank[] = new double[10];
+    int ExternalNodeNumber;
+    int InternalNodeNumber;
+    int k = 1; // For Traversing
+    int ITERATION_STEP = 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.printf("\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 (ITERATION_STEP <= 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 " + ITERATION_STEP + "th Step \n");
+
+        for (k = 1; k <= totalNodes; k++)
+          System.out.printf(" Page Rank of " + k + " is :\t" + this.pagerank[k] + "\n");
+
+        ITERATION_STEP = ITERATION_STEP + 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.printf("\n Final Page Rank : \n");
+      for (k = 1; k <= totalNodes; k++) {
+        System.out.printf(" Page Rank of " + k + " is :\t" + this.pagerank[k] + "\n");
+      }
+
+    }
+  }
+}
