floyd warshall algortihm for finding all shortest paths

Author: manjunath-asundi

algorithms/graph/shortest/Floydwarshall.java

@@ -0,0 +1,37 @@
+package algorithms.graph.shortest;
+
+/**
+ * @author Manjunath Asundi
+ * @see https://www.geeksforgeeks.org/floyd-warshall-algorithm-dp-16/# 
+ * Find all shortest paths from each vertex
+ */
+public class Floydwarshall {
+
+    public static void findAllShortestPaths(int matrix[][]) {
+        for (int k = 0; k < matrix.length; k++) 
+            for (int i = 0; i < matrix.length; i++) 
+                for (int j = 0; j < matrix[i].length; j++) 
+                    if (matrix[i][k] != Integer.MAX_VALUE && matrix[k][j] != Integer.MAX_VALUE
+                            && matrix[i][k] + matrix[k][j] < matrix[i][j])
+                        matrix[i][j] = matrix[i][k] + matrix[k][j];
+        printShortestPaths(matrix);
+    }
+
+    public static void printShortestPaths(int matrix[][]) {
+        for (int i = 0; i < matrix.length; i++) {
+            for (int j = 0; j < matrix[i].length; j++) {
+                if (matrix[i][j] != Integer.MAX_VALUE)
+                    System.out.print(matrix[i][j] + " ");
+                else
+                    System.out.print(-1 + " ");
+            }
+            System.out.println();
+        }
+    }
+
+    public static void main(String[] args) {
+        findAllShortestPaths(new int[][] { { 0, 5, Integer.MAX_VALUE, 10 },
+                { Integer.MAX_VALUE, 0, 3, Integer.MAX_VALUE }, { Integer.MAX_VALUE, Integer.MAX_VALUE, 0, 1 },
+                { Integer.MAX_VALUE, Integer.MAX_VALUE, Integer.MAX_VALUE, 0 } });
+    }
+}