Add BellmanFord.java implementation

Author: InbarAbraham

BellmanFord/BellmanFord.java

@@ -0,0 +1,65 @@
+import java.util.*;
+
+class BellmanFord {
+    // Function implementing the Bellman-Ford algorithm
+    public static void bellmanFord(int vertices, int edges[][], int source) {
+        // Array to hold the shortest distances
+        int dist[] = new int[vertices];
+        
+        // Initialize all distances to infinity, except for the source vertex
+        Arrays.fill(dist, Integer.MAX_VALUE);
+        dist[source] = 0;
+        
+        // Step 1: The initial run over all edges in the graph
+        for (int i = 1; i < vertices - 1; i++) {
+            for (int[] edge : edges) {
+                int u = edge[0]; // Starting vertex
+                int v = edge[1]; // Ending vertex
+                int weight = edge[2]; // Edge weight
+                
+                if (dist[u] != Integer.MAX_VALUE && dist[u] + weight < dist[v]) {
+                    dist[v] = dist[u] + weight;
+                }
+            }
+        }
+
+        // Step 2: Check for negative-weight cycles
+        for (int[] edge : edges) {
+            int u = edge[0];
+            int v = edge[1];
+            int weight = edge[2];
+            
+            if (dist[u] != Integer.MAX_VALUE && dist[u] + weight < dist[v]) {
+                System.out.println("Graph contains negative weight cycle");
+                return;
+            }
+        }
+
+        // Print the shortest distances for all vertices
+        System.out.println("Vertex Distance from Source");
+        for (int i = 0; i < vertices; i++) {
+            System.out.println(i + "\t\t" + dist[i]);
+        }
+    }
+
+    public static void main(String[] args) {
+        // Number of vertices in the graph
+        int vertices = 5; 
+        int edges[][] = {
+            {0, 1, -1}, // Edge from vertex 0 to vertex 1 with weight -1
+            {0, 2, 4},  // Edge from vertex 0 to vertex 2 with weight 4
+            {1, 2, 3},  // Edge from vertex 1 to vertex 2 with weight 3
+            {1, 3, 2},  // Edge from vertex 1 to vertex 3 with weight 2
+            {1, 4, 2},  // Edge from vertex 1 to vertex 4 with weight 2
+            {3, 2, 5},  // Edge from vertex 3 to vertex 2 with weight 5
+            {3, 1, 1},  // Edge from vertex 3 to vertex 1 with weight 1
+            {4, 3, -3}  // Edge from vertex 4 to vertex 3 with weight -3
+        };
+
+        // The source vertex
+        int source = 0;
+        
+        // Call the Bellman-Ford algorithm
+        bellmanFord(vertices, edges, source);
+    }
+}