chore: Added BellmanFord (#679)

* Added BellmanFord

* Add References for BellmanFord

* Style code using standard.js

* Add tests and modify code

* Fixed BellmanFord test file

* Add BellmanFord and tests

Graphs/test/BellmanFord.test.js

@@ -0,0 +1,34 @@
+import { BellmanFord } from '../BellmanFord.js'
+
+test('Test Case 1', () => {
+  const V = 5
+  const E = 8
+  const destination = 3
+  const graph = [[0, 1, -1], [0, 2, 4],
+    [1, 2, 3], [1, 3, 2],
+    [1, 4, 2], [3, 2, 5],
+    [3, 1, 1], [4, 3, -3]]
+  const dist = BellmanFord(graph, V, E, 0, destination)
+  expect(dist).toBe(-2)
+})
+test('Test Case 2', () => {
+  const V = 6
+  const E = 9
+  const destination = 4
+  const graph = [[0, 1, 3], [0, 3, 6],
+    [0, 5, -1], [1, 2, -3],
+    [1, 4, -2], [5, 2, 5],
+    [2, 3, 1], [4, 3, 5], [5, 4, 2]]
+  const dist = BellmanFord(graph, V, E, 0, destination)
+  expect(dist).toBe(1)
+})
+test('Test Case 3', () => {
+  const V = 4
+  const E = 5
+  const destination = 1
+  const graph = [[0, 3, -1], [0, 2, 4],
+    [3, 2, 2], [3, 1, 5],
+    [2, 1, -1]]
+  const dist = BellmanFord(graph, V, E, 0, destination)
+  expect(dist).toBe(0)
+})