10+ Cognizant Program Analyst Interview Questions and Answers

Given an integer 'N', find the final single-digit value by summing its digits iteratively.

• Iteratively sum the digits of the given integer until the result is a single-digit number

• Output the final single-digit integer for each test case

• Follow the constraints provided in the problem statement

Implement a function to determine if the binary representation of a given integer is a palindrome.

• Convert the integer to binary representation

• Check if the binary representation is a palindrome by comparing it with its reverse

• Return true if it is a palindrome, false otherwise

Calculate the Nth Fibonacci number efficiently using dynamic programming.

• Use dynamic programming to store previously calculated Fibonacci numbers to avoid redundant calculations.

• Start with base cases F(1) and F(2) as 1, then iteratively calculate F(n) using F(n-1) and F(n-2).

• Ensure the input N is within the constraints 1 <= N <= 10000.

• Return the Nth Fibonacci number as the output.

A program to determine if a given string is a palindrome considering only alphanumeric characters.

• Remove non-alphanumeric characters from the input string.

• Compare the string with its reverse to check for palindrome.

• Return true if the string is a palindrome, false otherwise.

Object-oriented programming concepts include encapsulation, inheritance, and polymorphism.

• Encapsulation: Bundling data and methods together in a class to hide implementation details.

• Inheritance: Creating new classes from existing ones, inheriting their properties and behaviors.

• Polymorphism: Objects of different classes can be treated as objects of a common superclass.

• Example: Encapsulation - A class 'Car' with private variables like 'speed' and public methods like 'accelerate...read more

Network security refers to the practice of protecting computer networks from unauthorized access or attacks.

• Network security involves implementing various measures to prevent unauthorized access to a network, such as firewalls, intrusion detection systems, and virtual private networks (VPNs).

• It also includes ensuring the confidentiality, integrity, and availability of data transmitted over the network.

• Examples of network security threats include malware, phishing attacks, and...read more

An abstract class is a class that cannot be instantiated and is used as a base class for other classes.

• An abstract class can have abstract and non-abstract methods.

• Abstract methods have no implementation and must be implemented by the derived classes.

• An abstract class can have constructors and fields.

• An example of an abstract class is the Shape class, where the methods like area() and perimeter() are abstract and must be implemented by the derived classes like Circle and Rect...read more

Paging and Segmentation are memory management techniques used by operating systems.

• Paging divides memory into fixed-size pages and stores them in physical memory.

• Segmentation divides memory into logical segments and stores them in physical memory.

• Both techniques allow for efficient use of memory and protection of memory from unauthorized access.

• Examples of operating systems that use paging and segmentation include Windows and Linux.

Run time mapping between pages and frames is the process of mapping virtual memory pages to physical memory frames during program execution.

• During program execution, the operating system maps virtual memory pages to physical memory frames to ensure efficient memory management.

• This mapping is done dynamically and can change as the program runs.

• The mapping is maintained in a page table, which is used by the operating system to translate virtual addresses to physical addresses.

• F...read more

Explanation of how sorting and searching complexities are derived.

• Sorting and searching algorithms have different complexities depending on the algorithm used.

• Sorting algorithms can be classified as O(n^2) or O(n log n) depending on the algorithm used.

• Searching algorithms can be classified as O(n) or O(log n) depending on the algorithm used.

• Complexities are derived by analyzing the number of operations required to complete the algorithm.

• For example, bubble sort has a complexi...read more

Indexes in SQL are data structures that improve the speed of data retrieval operations on a database table.

• Indexes are created on columns in a table to quickly retrieve rows based on the values in those columns.

• They can be unique, allowing only unique values to be stored in the indexed column.

• Examples of indexes include primary keys, which uniquely identify each row in a table, and foreign keys, which establish relationships between tables.

Critical section is a part of code that must not be executed by more than one thread at a time.

• It is used in multi-threaded programming to avoid race conditions.

• It is usually protected by locks or semaphores.

• Examples include updating shared variables or accessing shared resources.

• It is important for ensuring data consistency and preventing deadlocks.

Array, LinkedList, and ArrayList are data structures used to store and manipulate collections of elements.

• Arrays are fixed in size and can only store elements of the same data type.

• LinkedLists are dynamic in size and can store elements of different data types.

• ArrayLists are dynamic in size and can only store elements of the same data type.

• Arrays have faster access time for elements, while LinkedLists have faster insertion and deletion time.

• ArrayLists are a hybrid of Arrays an...read more

Code for critical section in C/Java/C++

• Use mutex or semaphore to protect critical section

• In C/C++, use pthread_mutex_lock() and pthread_mutex_unlock()

• In Java, use synchronized keyword

• In C++, use std::mutex and std::lock_guard

• Ensure only one thread can access critical section at a time

For loop is used for iterating over a sequence while while loop is used for executing a block of code repeatedly.

• For loop is used when the number of iterations is known beforehand

• While loop is used when the number of iterations is not known beforehand

• For loop is faster than while loop for iterating over a sequence

• While loop is useful for creating an infinite loop until a certain condition is met

One new technology I know about is blockchain, a decentralized and secure way to store and transfer data.

• Blockchain is a distributed ledger technology that securely records transactions across multiple computers.

• It is most commonly known for being the technology behind cryptocurrencies like Bitcoin.

• Blockchain has applications beyond finance, such as supply chain management, voting systems, and healthcare records.

• Smart contracts, which are self-executing contracts with the ter...read more

The port numbers for Windows and Linux VMs depend on the specific application or service being used.

• Port numbers can vary depending on the specific application or service being used on the VMs.

• Common port numbers for Windows VMs include 3389 for Remote Desktop Protocol and 445 for SMB file sharing.

• Common port numbers for Linux VMs include 22 for SSH and 80 for HTTP.

• It is important to ensure that the necessary ports are open and properly configured for the VMs to function corr...read more