Left Side View of Binary Tree in DSA Javascript - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the Left Side View of a Binary Tree?

It is the list of nodes visible when the tree is seen from the left side. Only the first node at each level from the left is included.

beginner

Which tree traversal method is commonly used to get the Left Side View of a Binary Tree?

Level order traversal (Breadth-First Search) is commonly used, visiting nodes level by level and picking the first node at each level.

intermediate

In the Left Side View, if a node has no left child but has a right child, which child appears in the view?

The right child will appear in the left side view if there is no left child at that level, because it is the first visible node from the left at that level.

beginner

What data structure helps to keep track of nodes at each level when finding the Left Side View?

A queue is used to perform level order traversal, helping to process nodes level by level.

intermediate

How do you ensure only the first node at each level is added to the Left Side View during traversal?

By adding the first node encountered at each level to the result before processing other nodes at the same level.

What does the Left Side View of a binary tree represent?

A Nodes visible from the right side, one per level

B Nodes visible from the left side, one per level

C All leaf nodes

D All nodes in in-order traversal

The left side view shows the first node visible at each level when looking from the left.

Which traversal technique is best suited to find the Left Side View?

A Level order traversal

B Pre-order traversal

C Post-order traversal

D In-order traversal

Level order traversal visits nodes level by level, making it easy to pick the first node at each level.

If a node has no left child but has a right child, will the right child appear in the Left Side View?

A No, only left children appear

B Only if the tree is balanced

C No, it will be skipped

D Yes, if it is the first node at that level

The first node at each level is included regardless of being left or right child.

What data structure is commonly used to implement level order traversal?

A Stack

B Set

C Queue

D Map

A queue helps process nodes in FIFO order, perfect for level order traversal.

How do you identify the first node at each level during traversal?

A By checking if it is the first node dequeued at that level

B By checking if it has a left child

C By checking if it is a leaf node

D By checking if it is the last node at that level

The first node dequeued at each level is the leftmost node visible from the left side.

Explain how to find the Left Side View of a Binary Tree using level order traversal.

Think about visiting nodes one level at a time and picking the first node you see.

Describe what happens in the Left Side View when a node has no left child but has a right child.

Consider visibility from the left side when left child is missing.