update: BSF for BST

Author: ashokdey

src/_DataStructures_/Trees/BinarySearchTree/index.js

@@ -3,6 +3,7 @@ const Node = require('./Node');
 
 class BinarySearchTree {
   constructor(value) {
+    if (!value) throw new Error('Root node value required');
     this.root = new Node(value);
   }
 

src/_Problems_/bfs-bst/index.js

@@ -0,0 +1,32 @@
+const BST = require('../../_DataStructures_/Trees/BinarySearchTree');
+const Queue = require('../../_DataStructures_/Queue');
+
+function traverseBFS(root) {
+  let temp = root;
+  const arr = [];
+  const nodeQueue = new Queue();
+
+  if (root === null) {
+    return arr;
+  }
+
+  while (temp !== null) {
+    arr.push(temp.value);
+    if (temp.leftChild) nodeQueue.enqueue(temp.leftChild);
+    if (temp.rightChild) nodeQueue.enqueue(temp.rightChild);
+    temp = nodeQueue.dequeue();
+  }
+  return arr;
+}
+
+const myBST = new BST(51);
+
+[10, 34, 32, 12, 90, 54, 61, 2, 71, 9].forEach(e => myBST.add(e));
+
+const preOrderElements = myBST.traversePreorder();
+const levelOrderElements = traverseBFS(myBST.root);
+
+// eslint-disable-next-line no-console
+console.log(preOrderElements);
+// eslint-disable-next-line no-console
+console.log(levelOrderElements);