Added Kahn's Algorithm (Topological Sort) in JavaScript

Author: durgesh846

Graphs/KahnsAlgorithm.js

@@ -0,0 +1,41 @@
+// Kahn's Algorithm for Topological Sort
+function kahnTopologicalSort(vertices, edges) {
+  const adj = new Map();
+  const indegree = new Array(vertices).fill(0);
+
+  // Build adjacency list & indegree count
+  for (let [u, v] of edges) {
+    if (!adj.has(u)) adj.set(u, []);
+    adj.get(u).push(v);
+    indegree[v]++;
+  }
+
+  const queue = [];
+  for (let i = 0; i < vertices; i++) {
+    if (indegree[i] === 0) queue.push(i);
+  }
+
+  const topo = [];
+  while (queue.length > 0) {
+    const node = queue.shift();
+    topo.push(node);
+
+    if (adj.has(node)) {
+      for (let neigh of adj.get(node)) {
+        indegree[neigh]--;
+        if (indegree[neigh] === 0) queue.push(neigh);
+      }
+    }
+  }
+
+  if (topo.length !== vertices) {
+    throw new Error("Graph has a cycle, topological sort not possible");
+  }
+
+  return topo;
+}
+
+// Example usage
+const vertices = 6;
+const edges = [[5,2],[5,0],[4,0],[4,1],[2,3],[3,1]];
+console.log("Topological Sort:", kahnTopologicalSort(vertices, edges));