Right Side View of Binary Tree in DSA Typescript - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to initialize the result array for storing the right side view nodes.

DSA Typescript

const rightSideView = (root: TreeNode | null): number[] => {
  const result: number[] = [1];
  if (!root) return result;
  // further code
};

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

Anull

B{}

C[]

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using {} which is an object, not an array.

Using null or 0 which are not arrays.

We initialize result as an empty array [] to store the right side view nodes.

2fill in blank

medium

Complete the code to perform a breadth-first search using a queue initialized with the root node.

DSA Typescript

const queue: (TreeNode | null)[] = [1];
while (queue.length > 0) {
  // processing nodes
}

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

A[null]

Broot

C[]

D[root]

Attempts:

3 left

💡 Hint

Common Mistakes

Using root without array brackets causes errors.

Starting with empty array means no nodes to process.

We start the queue with the root node inside an array: [root].

3fill in blank

hard

Fix the error in the code to add the rightmost node's value of the current level to the result array.

DSA Typescript

for (let i = 0; i < levelSize; i++) {
  const node = queue.shift()!;
  if (i === [1]) {
    result.push(node.val);
  }
  // enqueue children
}

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

AlevelSize - 1

B0

ClevelSize

Di

Attempts:

3 left

💡 Hint

Common Mistakes

Using 0 adds the leftmost node instead.

Using levelSize causes out-of-bound index.

The rightmost node is at index levelSize - 1 in the current level.

4fill in blank

hard

Fill both blanks to enqueue the left and right children of the current node if they exist.

DSA Typescript

if (node.[1]) queue.push(node.[1]);
if (node.[2]) queue.push(node.[2]);

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

Aleft

Bright

Cval

Dparent

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'val' or 'parent' which are not child nodes.

Swapping left and right properties.

We check and enqueue node.left and node.right children.

5fill in blank

hard

Fill all three blanks to complete the function that returns the right side view of the binary tree.

DSA Typescript

const rightSideView = (root: TreeNode | null): number[] => {
  const result: number[] = [1];
  if (!root) return result;
  const queue: (TreeNode | null)[] = [2];
  while (queue.length > 0) {
    const levelSize = queue.length;
    for (let i = 0; i < levelSize; i++) {
      const node = queue.shift()!;
      if (i === levelSize - 1) {
        result.push(node.val);
      }
      if (node.left) queue.push(node.left);
      if (node.right) queue.push(node.right);
    }
  }
  return [3];
};

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

A[]

B[root]

Cresult

Dnull

Attempts:

3 left

💡 Hint

Common Mistakes

Returning null or queue instead of result.

Not initializing queue with root node.

Initialize result as [], queue as [root], and return result at the end.