BST Find Minimum Element in DSA Javascript - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to start searching for the minimum element from the root node.

DSA Javascript

function findMin(root) {
  let current = [1];
  while (current.left !== null) {
    current = current.left;
  }
  return current.data;
}

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

Aroot.right

Broot.left

Croot

Dnull

Attempts:

3 left

💡 Hint

Common Mistakes

Starting from root.left skips the root node which might be the minimum.

Starting from root.right goes to the right subtree which has larger values.

We start from the root node to find the minimum element in a BST.

2fill in blank

medium

Complete the code to move to the left child node while searching for the minimum.

DSA Javascript

function findMin(root) {
  let current = root;
  while (current.[1] !== null) {
    current = current.left;
  }
  return current.data;
}

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

Aright

Bleft

Cnode

Dchild

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'right' instead of 'left' will go to larger values.

Using 'child' or 'node' are not valid properties.

We move left because the smallest value in a BST is always in the leftmost node.

3fill in blank

hard

Fix the error in the return statement to correctly return the minimum value.

DSA Javascript

function findMin(root) {
  let current = root;
  while (current.left !== null) {
    current = current.left;
  }
  return current.[1];
}

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

Adata

Bvalue

Cval

Dmin

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'value' or 'val' which are not defined properties.

Returning 'min' which is not a property of the node.

The node's value is stored in the 'data' property, so we return current.data.

4fill in blank

hard

Fill both blanks to create a function that returns null if the tree is empty and finds the minimum otherwise.

DSA Javascript

function findMin(root) {
  if (root === [1]) {
    return null;
  }
  let current = root;
  while (current.[2] !== null) {
    current = current.left;
  }
  return current.data;
}

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

Anull

Bundefined

Croot

Dleft

Attempts:

3 left

💡 Hint

Common Mistakes

Checking root against undefined instead of null.

Using 'right' instead of 'left' in the while loop.

We check if root is null to handle empty trees, and traverse left to find the minimum.

5fill in blank

hard

Fill all three blanks to implement a recursive function that finds the minimum element in a BST.

DSA Javascript

function findMinRecursive(node) {
  if (node === [1]) {
    return null;
  }
  if (node.[2] === [3]) {
    return node.data;
  }
  return findMinRecursive(node.left);
}

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

Anull

Bundefined

Dleft

Attempts:

3 left

💡 Hint

Common Mistakes

Using undefined instead of null for checks.

Checking right child instead of left child.

The base case checks if node is null, then if left child is null, return current node's data.