1. Data Structures (Tree Traversals)

Asked to explain and write the algorithms for Inorder, Preorder, and Postorder traversal of a binary tree.

Follow-up: difference between DFS and BFS traversals.

1. C/C++ Programming Concepts

Questions around:

• Memory & Pointers → how pointers work, pointer arithmetic, dangling pointers.
• Pass by value vs pass by reference in C/C++.

A question on JWT (JSON Web Token) – concept, usage in authentication, and security aspects.

1. Tree Coding Question

Problem: Check if a target value exists along any root-to-leaf path.

Required to construct the full binary tree and then write the function for path-sum/target check.

Expected to implement full code (not just pseudo code).

1. Bit Manipulation Problem

A logic-based coding problem using bitwise operators.

Example (not exact wording): Given a number, perform certain bit manipulations (like checking set bits, or toggling).

1. Next Greater Element (Variation)

Classic stack-based problem: find the next greater element for each element in an array.

Variation was asked (could be circular array or next greater frequency element).

Needed optimized solution (O(n) with stack).

Questions on pointers and memory (pointer arithmetic, dangling pointers).

Difference between pass by value and pass by reference, with code examples.

Some discussion around dynamic memory allocation and how it's managed in C++.

Emphasis on understanding how things work at a low-level in memory, not just syntax.