feat: kanns Algorithm included

Author: RaviSadam

Graphs/KannsAlgorithm.js

@@ -0,0 +1,47 @@
+
+/**
+ * @author {RaviSadam}
+ * @name kannsAlgorithm
+ * @description - 
+ * Kann's Algorithm implementation in JavaScript
+ * @summary
+ * Kann's Algorithm is used for topological sorting in directed acyclic graphs
+ * 
+ * @param graph - Graph [[v1,v2],[v3,v4,v5]..]
+ * @param n - number of vertices
+ * @returns {Array} - Empty array if cycle is detected or else result array;
+ * 
+ */
+
+export function kannsAlgorithm(graph, n) {
+    if (n === null || n === undefined)
+        throw Error('Invalid v is given');
+    const inorder = Array(n).fill(0);
+    const result = [];
+    for (let entry of graph) {
+        for (let edge of entry) {
+            inorder[edge] += 1;
+        }
+    }
+    const queue = [];
+    console.log(inorder);
+    for (let i = 0; i < n; i++) {
+        if (inorder[i] === 0) {
+            queue.push(i);
+        }
+    }
+    while (queue.length != 0) {
+        const node = queue[0];
+        result.push(node);
+        queue.splice(0, 1);
+        for (let nei of graph[node]) {
+            inorder[nei] -= 1;
+            if (inorder[nei] == 0) {
+                queue.push(nei);
+            }
+        }
+    }
+    if (result.length != n)
+        return [];
+    return result;
+}