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Which of the following data structures has constant average time complexity O(1) for search, insert, and delete operations?

Worked Solution & Logic

Explanation: A Hash Table utilizes a hash function to map keys to bucket indexes, providing $O(1)$ expected time complexity for insertion, lookup, and deletion when collisions are minimized.

What is the worst-case time complexity of the QuickSort algorithm?

Worked Solution & Logic

While QuickSort achieves O(n log n) average case time complexity, in the worst-case scenario (such as when the array is already sorted and the extreme element is consistently chosen as pivot without randomization), the recursion tree degenerates to depth $n$, producing O(n²) comparisons.

Which data structure is primarily used to implement Breadth-First Search (BFS) on a graph?

Worked Solution & Logic

BFS explores nodes level by level in First-In-First-Out order, which requires a Queue. (A Stack is used for Depth-First Search - DFS).

Which of the following is NOT one of Coffman's four necessary conditions for a Deadlock to occur in an operating system?

Worked Solution & Logic

The four Coffman conditions for deadlock are:
1. Mutual Exclusion
2. Hold and Wait
3. No Preemption (resources cannot be forcibly taken)
4. Circular Wait.
'Preemption Allowed' prevents deadlock, so it is NOT a deadlock condition.

In a relational database, what normal form requires that every non-prime attribute be fully functionally dependent on the entire primary key, eliminating partial dependencies?

Worked Solution & Logic

A relation is in Second Normal Form (2NF) if it is in 1NF and no non-prime attribute is partially dependent on any candidate key of the table (eliminating partial functional dependency). 3NF eliminates transitive dependencies.

In the TCP 3-way handshake, what is the correct sequence of packet flags exchanged between client and server?

Worked Solution & Logic

The standard TCP three-way handshake connection sequence is:
1. Client sends SYN to Server.
2. Server responds with SYN-ACK back to Client.
3. Client acknowledges with ACK to Server.

What is the maximum number of nodes in a binary tree of height 'h' (where height of root node is 0)?

Worked Solution & Logic

A full binary tree has $2^0$ nodes at level 0, $2^1$ at level 1, ..., $2^h$ at level $h$.
Sum of the geometric progression = $$\sum_{i=0}^h 2^i = 2^{h+1} - 1$$
For instance, for $h = 2$, max nodes = $2^3 - 1 = 7$.

Which process scheduling algorithm can suffer from the 'Convoy Effect'?

Worked Solution & Logic

The Convoy Effect occurs in FCFS (First-Come, First-Served) scheduling when a CPU-intensive process holds the processor for a long burst, causing all subsequent I/O-bound short processes to wait behind it like a slow convoy.

In Object-Oriented Programming, which principle states that 'Derived classes must be substitutable for their base classes without altering the correctness of the program'?

Worked Solution & Logic

The 'L' in SOLID stands for the Liskov Substitution Principle (LSP), formulated by Barbara Liskov. It dictates that if $S$ is a subtype of $T$, then objects of type $T$ may be replaced with objects of type $S$ without modifying any of the desirable properties of the program.

What is the average and worst-case time complexity of searching for an element in a balanced Binary Search Tree (AVL or Red-Black Tree) containing N nodes?

Worked Solution & Logic

In self-balancing binary search trees (AVL Trees and Red-Black Trees), rotational balancing guarantees that tree height is strictly maintained at $h = O(\log N)$. Thus, both average and worst-case search, insertion, and deletion operations require $O(\log N)$ time.

Which SQL constraint uniquely identifies each record in a database table while strictly disallowing NULL values?

Worked Solution & Logic

A PRIMARY KEY uniquely identifies every tuple in a table and implicitly enforces both UNIQUE and NOT NULL constraints. A standalone UNIQUE constraint allows one or more NULL entries depending on the SQL database engine.

In the OSI 7-Layer Reference Model, which layer is responsible for logical IP addressing and packet routing across intermediate subnets?

Worked Solution & Logic

The Network Layer (Layer 3) handles logical host addressing (IPv4/IPv6), packet forwarding, subnet routing protocols (BGP, OSPF), and path determination.

In Git version control, which command creates a new branch named 'feature-auth' and immediately checks out into it?

Worked Solution & Logic

The command git checkout -b feature-auth is shorthand for two operations: creating the branch (git branch feature-auth) and switching the working tree head to it (git checkout feature-auth). In mode Git, git switch -c feature-auth is also supported.

A program must undo the most recently completed action first. Which data structure directly matches this removal order?

Worked Solution & Logic

A stack follows last-in

How many distinct bit patte s can an 8-bit unsigned integer represent?

Worked Solution & Logic

Each bit has two possible values

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Core Technical Computer Science MCQs

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