300+ Cognizant Interview Questions and Answers

Merge sort and Quick sort are sorting algorithms used to sort arrays of data.

• Merge sort is a divide and conquer algorithm that divides the input array into two halves, sorts each half recursively, and then merges the sorted halves.

• Quick sort is also a divide and conquer algorithm that selects a pivot element and partitions the array around the pivot, sorting the two resulting sub-arrays recursively.

• Merge sort has a time complexity of O(n log n) and is stable, but requires add...read more

Comparison of heights of two soldiers chosen based on different criteria from a grid of soldiers.

• Soldier A is chosen based on tallest men from every column and shortest among them.

• Soldier B is chosen based on shortest men from every row and tallest among them.

• The height of Soldier A and Soldier B cannot be determined without additional information about the grid of soldiers.

To determine if a point is inside a polygon, use the ray casting algorithm.

• Create a line from the point to a point outside the polygon

• Count the number of times the line intersects with the polygon edges

• If the count is odd, the point is inside the polygon; otherwise, it is outside

To find and remove a loop in a Linked List, we can use Floyd's Cycle Detection Algorithm.

• Use two pointers, slow and fast, to detect if there is a loop in the Linked List

• If the two pointers meet at some point, there is a loop

• To remove the loop, set one of the pointers to the head of the Linked List and move both pointers one step at a time until they meet again

• The meeting point is the start of the loop, set the next pointer of this node to NULL to remove the loop

To remove unnecessary parenthesis from an expression, we need to apply a set of rules to identify and eliminate them.

• Identify and remove parenthesis around single variables or constants

• Identify and remove parenthesis around expressions with only one operator

• Identify and remove parenthesis around expressions with operators of equal precedence

• Identify and remove parenthesis around expressions with operators of different precedence

• Apply the rules recursively until no more unnece...read more

Distribute 50 white and 100 black eggs in one bag and 50 white and 0 black eggs in the other bag.

• Distribute the black eggs in one bag and white eggs in the other bag

• Ensure that both bags have equal number of white eggs

• The bag with black eggs will have a higher probability of getting a black egg

Design a clock to know time in any region of the world with built-in calculation device.

• Create a clock with a world map and time zones marked on it.

• Use the built-in calculation device to calculate the time difference between the user's location and the desired location.

• Display the time in the desired location on the clock face.

• Allow the user to input the desired location using a keypad or touchscreen.

• Include a database of time zones and their offsets for accurate calculations...read more

Famous puzzles including measuring 4 liters from 3 and 5 liters and 3 bulbs and 3 switches.

• Measuring 4 liters puzzle involves filling 5 liter jug and transferring to 3 liter jug to get 4 liters

• 3 bulbs and 3 switches puzzle involves turning on one switch, waiting a few minutes, turning it off, and turning on another switch

• These puzzles test problem-solving skills and creativity

Given an array of integers, find if a subarray exists whose sum equals to k.

• Use a hashmap to store the prefix sum and its frequency.

• Iterate through the array and check if the difference between current prefix sum and k exists in the hashmap.

• If it exists, then a subarray with sum k exists.

• Time complexity: O(n), Space complexity: O(n).

Given a Sudoku board, find possible numbers for an empty cell.

• Iterate through empty cells and check possible numbers using row, column, and box constraints.

• Use a set to keep track of possible numbers for each empty cell.

• Return the set of possible numbers for the given empty cell.

The lead generation process involves identifying potential customers and nurturing them into qualified leads.

• Research and identify target audience

• Create compelling content and offers

• Promote content through various channels

• Capture leads through forms or landing pages

• Nurture leads through email marketing or lead scoring

• Qualify leads through lead qualification criteria

• Pass qualified leads to sales team for conversion

Finding the longest last occurring word in a sentence with multiple whitespace.

• Split the sentence into words using whitespace as delimiter

• Reverse the list of words

• Iterate through the list and find the first occurrence of each word

• Calculate the length of each last occurring word

• Return the longest last occurring word

Priority queue is a data structure that stores elements with priority levels and retrieves them in order of priority.

• Priority queue is implemented using a heap data structure.

• Stack can be implemented using a priority queue by assigning higher priority to the most recently added element.

• Queue can be implemented using a priority queue by assigning higher priority to the oldest element.

We support various project types including FTFP, TnM, and Fixed Bid.

• FTFP (Fixed Time Fixed Price) - project with a fixed timeline and budget

• TnM (Time and Material) - project with a flexible timeline and budget based on actual hours worked and materials used

• Fixed Bid - project with a fixed budget but flexible timeline

• Examples: FTFP - website development, TnM - software maintenance, Fixed Bid - infrastructure upgrade

Find the maximum product of three integers in an array.

• Sort the array in descending order.

• Check the product of the first three numbers and the product of the first and last two numbers.

• Return the maximum of the two products.

Find length of longest consecutive sub array forming an AP from given array of integers.

• Sort the array in ascending order

• Iterate through the array and find the longest consecutive sub array forming an AP

• Use a variable to keep track of the length of the current consecutive sub array forming an AP

• Use another variable to keep track of the length of the longest consecutive sub array forming an AP seen so far

To find which ball is hollow, we can compare their weights.

• Weigh both balls on a scale and compare their weights.

• The hollow ball will weigh less than the solid ball.

• If the difference in weight is not noticeable, try rolling both balls on a flat surface.

• The hollow ball will roll differently due to its hollow center.

Implementing qsort() or custom sort() function in C/C++ to sort any type of data based on user-defined criteria.

• Use qsort() function in C or sort() function in C++ to sort the data.

• For custom sorting, define a comparison function that takes two elements and returns a negative, zero, or positive value based on their order.

• The comparison function should be passed as a parameter to qsort() or sort() function.

• Ensure the comparison function handles different data types and user-de...read more

Find 5 missing numbers in an array of size 95 containing numbers in range 1 to 100.

• Create a boolean array of size 100 and mark the present numbers

• Iterate through the boolean array and find the missing numbers

• Alternatively, use a HashSet to store the present numbers and find the missing ones

The four storage classes in C are auto, register, static, and extern.

• Auto: default storage class for all local variables

• Register: used to define local variables that should be stored in a register instead of RAM

• Static: used to define local variables that retain their value between function calls

• Extern: used to declare a global variable that is defined in another file

Static variables are allocated memory in the data segment of the program's memory space.

• Static variables have a fixed memory location throughout the program's execution.

• They are initialized to zero by default.

• If initialized explicitly, they are stored in the data segment.

• Static variables can be accessed by any function in the program.

Use the seesaw 3 times to find the person with different weight among 12 people on an island.

• Divide the 12 people into 3 groups of 4.

• Compare 2 groups on the seesaw, then narrow down the group with the different person.

• Take the 4 people from the identified group and compare 2 of them on the seesaw to find the person with different weight.

Separate 100 coins with 60 heads and 40 tails into 2 groups with equal number of tails.

• Separate 40 coins and put them in one group

• Put the remaining 60 coins in the other group

• Since both groups have 40 tails, the remaining coins must have 20 tails each

C function to sort an array in ascending order

• Use bubble sort algorithm to sort the array

• Create a function that takes array and its size as input

• Test cases: empty array, array with one element, array with duplicates

• Generalize the function by making it work for any array of integers

Copying fixed number of bytes from source to destination and its test cases.

• Ensure source and destination are not overlapping

• Check if the number of bytes to be copied is greater than the available space in the destination

• Handle cases where source or destination is NULL

• Test cases should cover all possible scenarios including edge cases

To find a new array where each element is the product of all elements in the original array except the element at that index without using division operator.

• Iterate through the array and calculate the product of all elements to the left of the current index for each element.

• Iterate through the array in reverse and calculate the product of all elements to the right of the current index for each element.

• Multiply the results from the two steps above to get the final array.

Search for an element in a sorted 2D array and return its index if found

• Start from the top right corner and compare the target element with the current element

• If the target is smaller, move left; if larger, move down

• Repeat until the element is found or all elements are checked

To make the most optimized triangular mesh, use a Delaunay triangulation algorithm.

• Use a Delaunay triangulation algorithm to connect the points with triangles.

• Delaunay triangulation ensures that no point is inside the circumcircle of any triangle.

• This algorithm creates triangles with the minimum angle possible, resulting in an optimized mesh.

• Popular algorithms for Delaunay triangulation include Bowyer-Watson and incremental algorithms.

Given an integer, determine which byte is zero.

• Convert the integer to a byte array using bitwise operations.

• Iterate through the byte array and check for a zero value.

• Return the index of the zero byte.

• Consider endianness when converting to byte array.

The running time for insertion, deletion, and searching in a sorted array is O(log n), while in an unsorted array it is O(n).

• In a sorted array, insertion, deletion, and searching can be done using binary search, which has a time complexity of O(log n).

• In an unsorted array, insertion and deletion require shifting elements, resulting in a time complexity of O(n). Searching also requires checking each element, resulting in a time complexity of O(n).

To break a linked list into two lists, we can traverse the list and add nodes to respective lists based on their value.

• Traverse the linked list and add nodes to positive or negative list based on their value

• Create two empty lists for positive and negative nodes

• Iterate through the linked list and add nodes to respective lists

• Join the two lists at the end to get the final result

Code to find number of combinations of reaching step N by ball falling from staircase with 1 or 2 steps per jump.

• Use dynamic programming to solve the problem

• Create an array to store the number of ways to reach each step

• Initialize the array with base cases for steps 0, 1, and 2

• Use a loop to fill in the array for steps 3 to N

• The number of ways to reach step i is the sum of the number of ways to reach step i-1 and i-2

• Return the value at the Nth index of the array

Find the Next Greatest Element to the right for each element in an array of strings.

• Iterate through the array from right to left

• Use a stack to keep track of elements

• Pop elements from stack until a greater element is found

• If no greater element is found, assign -1

• Return the result array

To check endianness, create a 4-byte integer with a known value and check the byte order.

• Create a 4-byte integer with a known value

• Check the value of the first byte to determine endianness

• If the first byte is the least significant, the machine is little endian

• If the first byte is the most significant, the machine is big endian

Finding space and time complexity of a recursive function.

• Space complexity is the amount of memory used by the function.

• Time complexity is the amount of time taken by the function to execute.

• Recursive functions have higher space complexity due to the call stack.

• Time complexity can be calculated using Big O notation.

• Examples of recursive functions include factorial and Fibonacci sequence.

Return all root to leaf node paths in a binary tree with row, col and value.

• Traverse the binary tree recursively and keep track of the current path.

• When a leaf node is reached, add the path to the result array.

• Include row, col and value of each node in the path.

• Use an array of strings to store the paths.

I would buy Company A as it has a lower PE ratio, indicating potentially better value for the investment.

• Company A has a lower PE ratio of 10, suggesting it may be undervalued compared to Company B with a PE ratio of 15.

• Investors typically prefer stocks with lower PE ratios as they offer better value for the price paid.

• However, other factors such as growth prospects, industry trends, and financial health should also be considered before making a decision.

APIs are tools that allow different software applications to communicate with each other. An example of maximum use is integrating a payment gateway API into an e-commerce website.

• API stands for Application Programming Interface

• APIs allow different software applications to communicate with each other

• APIs can be used to integrate different functionalities into a software application

• An example of maximum use is integrating a payment gateway API into an e-commerce website

We track margins by closely monitoring project expenses and revenue.

• We maintain a detailed project budget that includes all expenses and revenue.

• We regularly review and update the budget to ensure accuracy.

• We track actual expenses and revenue against the budget to identify any variances.

• We use this information to make adjustments and ensure we are meeting our margin targets.

• We also analyze historical data to identify trends and make informed decisions for future projects.

Free uses metadata stored in the heap to determine the number of memory blocks to delete for arrays.

• Free stores metadata about the size of the allocated memory block in the heap.

• Free uses this metadata to determine the number of memory blocks to delete for arrays.

• For example, if an array of 10 integers was allocated, the metadata would indicate the size of the block as 40 bytes.

• Free would then use this information to delete all 40 bytes of memory allocated for the array.

I handle change requests with clients by following a structured process and ensuring clear communication throughout.

• Acknowledge the request and gather all necessary information

• Assess the impact on project timeline, budget, and resources

• Communicate the potential impact to the client and propose solutions

• Obtain client approval before implementing any changes

• Document all changes and update project plan accordingly

To merge two double linked lists, traverse to the end of the first list and connect it to the head of the second list.

• Traverse to the end of the first list

• Connect the last node of the first list to the head of the second list

• If the lists are singly linked, we need to traverse to the end of the first list and connect it to the head of the second list. But we also need to keep track of the last node of the first list to connect it to the head of the second list.

• Example: list1: ...read more

Static objects can be used to print something before main() execution.

• Static objects are initialized before main() execution

• They can be used to print something before main()

• Example: static int x = printf("Hello World!");

• Output: Hello World! will be printed before main() execution

Add minus sign to some numbers in array to make sum zero

• Identify the sum of all numbers in the array

• If sum is already zero, return the array as is

• If sum is positive, add minus sign to one or more positive numbers until sum becomes zero

• If sum is negative, add minus sign to one or more negative numbers until sum becomes zero

Multithreading allows multiple threads to run concurrently. Global and static variables are stored in a shared memory space and accessed by all threads.

• Multithreading enables concurrent execution of multiple threads.

• Global and static variables are stored in a shared memory space accessible by all threads.

• Threads can read and modify the values of global and static variables.

• Synchronization mechanisms like locks or semaphores are used to prevent data races and ensure thread saf...read more

Integrating Power BI with Adobe Captivate Prime can provide valuable insights for sales management.

• Power BI can be used to create interactive dashboards and reports that can be integrated with Adobe Captivate Prime.

• This integration can help sales managers to track the progress of their sales team and identify areas for improvement.

• Project work on Power BI can involve creating custom reports and dashboards that are tailored to the specific needs of the sales team.

• For example, ...read more

Negotiating timelines with product owners or scrum teams in a waterfall model requires clear communication, prioritization, and flexibility.

• Communicate openly and regularly with the product owner and scrum team to understand project requirements and constraints.

• Prioritize tasks based on importance and impact on project timeline.

• Be flexible and willing to adjust timelines based on feedback and changes in project scope.

• Use tools like Gantt charts or project management software ...read more

To generate 0-7 with equal probability, use F() twice to generate a binary number and convert it to decimal.

• Call F() twice to generate two binary digits

• Combine the two binary digits to form a binary number

• Convert the binary number to decimal to get a number between 0-3

• Multiply the decimal number by 2 to get a number between 0-6

• Add 1 to the result to get a number between 1-7

OOPS stands for Object-Oriented Programming. It is a programming paradigm that uses objects and classes for code organization and reusability.

• OOPS allows for better code organization and reusability through the use of classes and objects.

• Encapsulation, inheritance, and polymorphism are key principles of OOPS.

• Examples of OOPS languages include Java, C++, and Python.

DBMS stands for Database Management System. It is used to manage and organize data efficiently. It provides data security, integrity, and easy access.

• DBMS helps in organizing and managing data efficiently.

• It ensures data security and integrity by providing access control and data encryption.

• DBMS allows for easy retrieval and manipulation of data through query languages like SQL.

• Examples of DBMS include MySQL, Oracle, and Microsoft SQL Server.

DSA stands for Data Structures and Algorithms. Web development is the process of creating websites and web applications.

• DSA involves organizing and storing data efficiently for quick access and manipulation

• Web development includes front-end (client-side) and back-end (server-side) development

• Examples of DSA include arrays, linked lists, and sorting algorithms

• Examples of web development technologies include HTML, CSS, JavaScript, and frameworks like React and Node.js

Find integer average of 4 unsigned integers without typecasting

• Add all the integers and divide by 4

• Use bit shifting to divide by 4

• Handle overflow by using long long data type

• Use unsigned int data type for input

A recursive function calls itself until a base case is reached, then returns the result to the previous call.

• Each call creates a new instance of the function on the call stack

• The function continues to call itself until a base case is reached

• Once the base case is reached, the function returns the result to the previous call

• The previous call then continues executing from where it left off

Test cases for Adobe Reader's save functionality

• Verify that the file is saved with the correct name and extension

• Check that the saved file can be opened and read without errors

• Test saving files with different sizes and formats

• Verify that the save dialog box appears when saving a file

• Check that the save operation can be cancelled without any issues

• Test saving files to different locations and verify that they are saved correctly

• Verify that the save operation does not overwrite ...read more

Print the leftmost element in each level of a binary tree.

• Use a queue to traverse the tree level by level.

• At each level, print the first node in the queue.

• Add the left and right child of the node to the queue if they exist.

• Repeat until the queue is empty.

To take design to an advanced level, one should focus on continuous learning, exploring new technologies, collaborating with others, and seeking feedback.

• Continuously learn and stay updated with the latest design trends and technologies.

• Explore new tools and software that can enhance the design process and improve efficiency.

• Collaborate with other designers, engineers, and stakeholders to gain different perspectives and insights.

• Seek feedback from users, clients, and colleagu...read more

FTFP is suitable for projects with well-defined requirements and stable scope, while TNM is suitable for projects with evolving requirements and uncertain scope.

• FTFP (Fixed Time Fixed Price) is suitable for projects with well-defined requirements and stable scope.

• TNM (Time and Material) is suitable for projects with evolving requirements and uncertain scope.

• FTFP is best suited for projects where the scope is clear and the requirements are well-defined.

• TNM is best suited for p...read more