solve bst inorder tree walk by recursion

Binary Search Tree/inorder_tree_walk.js

@@ -0,0 +1,11 @@
+function inorderTreeWalkByRecursion(root) {
+ if (root == null) return;
+
+ inorderTreeWalkByRecursion(root.left);
+ console.log(root.element);
+ inorderTreeWalkByRecursion(root.right);
+}
+
+module.exports = {
+ inorderTreeWalkByRecursion,
+}

Binary Search Tree/inorder_tree_walk.test.js

@@ -0,0 +1,35 @@
+const { inorderTreeWalkByRecursion } = require('./inorder_tree_walk');
+const { BinarySearchTree } = require('./BST');
+
+describe('Inorder Tree Walk', () => {
+ let bst;
+ let consoleLogSpy;
+
+ beforeEach(() => {
+ consoleLogSpy = jest.spyOn(console, 'log');
+ })
+
+ afterEach(() => {
+ jest.restoreAllMocks();
+ });
+
+ describe('By Recursion', () => {
+ it('should print null', () => {
+ const bst = new BinarySearchTree();
+
+ inorderTreeWalkByRecursion(bst.root);
+ })
+
+ it('should print out element using console', () => {
+ const bst = new BinarySearchTree();
+ bst.add(2);
+ bst.add(3);
+ bst.add(1);
+
+ inorderTreeWalkByRecursion(bst.root);
+ expect(consoleLogSpy).toHaveBeenNthCalledWith(1, 1);
+ expect(consoleLogSpy).toHaveBeenNthCalledWith(2, 2);
+ expect(consoleLogSpy).toHaveBeenNthCalledWith(3, 3);
+ })
+ })
+});