BST Delete Operation in DSA Javascript - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to find the minimum value node in a BST.

DSA Javascript

function findMinNode(node) {
  while (node.[1] !== null) {
    node = node.[1];
  }
  return node;
}

Drag options to blanks, or click blank then click option'

Achild

Bright

Cparent

Dleft

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'right' instead of 'left' will find the maximum, not minimum.

In a BST, the minimum value is found by going to the left child repeatedly until null.

2fill in blank

medium

Complete the code to delete a node with no children (leaf node) in BST.

DSA Javascript

if (node.left === null && node.right === null) {
  node = [1];
}

Drag options to blanks, or click blank then click option'

Anull

Bnode.right

Cnode.parent

Dnode.left

Attempts:

3 left

💡 Hint

Common Mistakes

Assigning node.left or node.right instead of null.

Deleting a leaf node means setting it to null.

3fill in blank

hard

Fix the error in the code to correctly replace a node with its right child when left child is null.

DSA Javascript

if (node.left === null) {
  node = node.[1];
}

Drag options to blanks, or click blank then click option'

Aright

Bchild

Cleft

Dparent

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'left' instead of 'right' causes wrong replacement.

If the left child is null, replace the node with its right child.

4fill in blank

hard

Fill both blanks to correctly find the inorder successor and replace the node's value.

DSA Javascript

let temp = findMinNode(node.[1]);
node.[2] = temp.data;

Drag options to blanks, or click blank then click option'

Aright

Bleft

Cdata

Dvalue

Attempts:

3 left

💡 Hint

Common Mistakes

Using left subtree or wrong property name for replacement.

The inorder successor is the minimum node in the right subtree. Replace node's data with successor's data.

5fill in blank

hard

Fill all three blanks to complete the recursive delete function for BST.

DSA Javascript

function deleteNode(node, key) {
  if (node === null) return null;
  if (key < node.data) {
    node.[1] = deleteNode(node.[2], key);
  } else if (key > node.data) {
    node.right = deleteNode(node.right, key);
  } else {
    if (node.left === null) return node.[3];
    else if (node.right === null) return node.left;
    let temp = findMinNode(node.right);
    node.data = temp.data;
    node.right = deleteNode(node.right, temp.data);
  }
  return node;
}

Drag options to blanks, or click blank then click option'

Aleft

Bright

Dparent

Attempts:

3 left

💡 Hint

Common Mistakes

Using right subtree for keys less than node data.

Returning wrong child when left is null.

When key is less, recurse on left subtree. Replace node.left with recursive call result. If left child is null, return right child.