SDE - 1

• What is Inheritance in OOP, and how does it promote code reuse and maintainability? (Learn)
• Explain the concepts of Encapsulation and Abstraction in OOP, and provide an example of how they can be used in a real-world scenario.
• What is the Diamond Problem in the context of multiple inheritance? How can it be resolved in different programming languages? (Learn)
• Compare and contrast the terms 'method overloading' and 'method overriding' in the context of OOP. Provide examples to illustrate the differences. (Learn)
• Discuss the advantages of using interfaces in OOP, and how they enable better design and flexibility in software development. Provide an example of a situation where interfaces would be more suitable than inheritance.

• Explain the difference between a primary key and a foreign key in a relational database. Provide an example scenario to illustrate their usage. (Learn)
• What is the ACID (Atomicity, Consistency, Isolation, Durability) principle in database transactions? How does it ensure data integrity and reliability? (Learn)
• Describe the differences between a SQL JOIN and a SUBQUERY. Provide an example of when you would use each and the advantages of one approach over the other. (Learn)
• Discuss the concepts of normalization and denormalization in the context of database design. When would you choose to denormalize a database, and what are the potential trade-offs?
• Explain the importance of indexing in a database. What types of indexes are commonly used, and how do they impact query performance? Provide an example of a scenario where indexing would significantly improve a query's execution time.

A doubly-linked list is a data structure that consists of sequentially linked nodes, and the nodes have reference to both the previous and the next nodes in the sequence of nodes.

You are given a sorted doubly linked list of size 'n'.

Remove all the duplicate nodes present in the linked list.

Example :

Input: Linked List: 1 <-> 2 <-> 2 <-> 2 <-> 3

Output: Modified Linked List: 1 <-> 2 <-> 3

Explanation: We will delete the duplicate values ‘2’ present in the linked list.

You have been given a Binary Tree of integers, find the minimum depth of this Binary Tree. The minimum depth of a Binary Tree is the number of nodes along the shortest path from the root node down to the nearest leaf node.

Note:

A leaf is a node with no children.

For example:

For the given binary tree

Output: 2
The shortest path is from root node 1 to leaf node 2 which contains 2 nodes in the path. Hence, the minimum depth is 2.

You are given a binary tree with ‘N’ nodes. Each node has an integer value associated with it. Your task is to print the leaf nodes and then remove these leaf nodes. Now, print the new leaf nodes and repeat the process until the tree becomes empty.

Note:

You don’t require to remove the leaf nodes. Just print the values in the required order.

The leaf nodes must be printed in a left to right order.

You are given an array/list 'asteroids' representing asteroids in a row.

For each element of the given array, its absolute value denotes the size of that asteroid, and its sign denotes the direction it moves in(+ve meaning right and -ve meaning left).

An asteroid with a weight of 0 denotes a massless asteroid that moves in the right direction.

All asteroids are moving at the same speed. Whenever two asteroids collide, the smaller asteroid gets destroyed.

If both asteroids are the same size, then both asteroids get destroyed. Two asteroids moving in the same direction never collide.

You are supposed to find the state of the asteroids after all collisions.

Example :

Input: ‘asteroids’ = [3,-2,4]

Output: [3, 4]

Explanation: The first asteroid will destroy the second asteroid. Hence, after the collision, the state of the asteroids will be [3,4].

Note:

You don’t need to print anything. Just implement the given function.