SDE - Intern

• Why do we need virtual memory when physical memory (RAM) already exists? How does virtual memory allow a process to use more memory than the available physical RAM? What are the advantages and disadvantages of virtual memory? (Learn)
• What is the role of paging in virtual memory management? (Learn)
• Can you explain how logical (virtual) address is converted into a physical address? (Learn)
• What is a page fault, and how does the operating system handle it step by step? (Learn)
• What is demand paging, and how is it different from loading all pages at once? (Learn)
• What are page replacement algorithms? Can you name a few and explain when they are used? (Learn)
• What is thrashing, and under what conditions does it occur? (Learn)

You are given an undirected graph with 'N' nodes and 'M' edges. The weight of each edge in the graph is one unit.

Given a source vertex 'src', you must return an array 'answer' of length 'N', where 'answer[i]' is the shortest path length between the source vertex 'src' and 'i'th vertex.

Note:

All the nodes are zero-based.

Example:

Input:
N=5, M=5, edges=[(0, 1), (1, 4), (2, 3), (2, 4), (3, 4)], src=1 
Output: 1 0 2 2 1

Explanation: The path from vertices are:-
(1->0) = 1 -> 0, path length is 1.
(1->1) = 1 -> 1, path length is 0.
(1->2) = 1 -> 4 -> 2, the path length is 2.
(1->3) = 1 -> 4 -> 3, path length is 2.
(1->4) = 1 -> 4, the path length is 1.
Hence we return [1, 0, 2, 2, 1]

For a given array with N elements, you need to find the length of the longest subsequence from the array such that all the elements of the subsequence are sorted in strictly increasing order.

Strictly Increasing Sequence is when each term in the sequence is larger than the preceding term.

For example:

[1, 2, 3, 4] is a strictly increasing array, while [2, 1, 4, 3] is not.

You are given an array consisting of 'N' distinct positive integers and a number 'K'. Your task is to find the kth largest element in the array.

Example:

Consider the array {2,1,5,6,3,8} and 'K' = 3, the sorted array will be {8, 6, 5, 3, 2, 1}, and the 3rd largest element will be 5.

Note:

1) Kth largest element in an array is the kth element of the array when sorted in non-increasing order. 

2) All the elements of the array are pairwise distinct.

• What are Semaphores? (Learn)
• What is Virtual Memory? (Learn)

• What is normalization? Explain different normal forms. (Learn)
• What is denormalization? When is it used? (Learn)
• What is a primary key, foreign key, and unique key? (Learn)
• Explain ACID properties in databases. (Learn)
• What is indexing? How does it improve query performance? (Learn)
• What is a deadlock? How can it be prevented? (Learn)

Design a scalable URL Shortening Service (similar to bit.ly).
The problem involved discussing functional and non-functional requirements, high-level architecture, database schema, scalability considerations, and handling high traffic efficiently.