Virtusa Consulting Services Web Developer Interview Questions and Answers

Network layers are a hierarchical way of organizing communication protocols.

• Network layers provide a modular approach to networking.

• Each layer has a specific function and communicates with adjacent layers.

• The OSI model has 7 layers, while the TCP/IP model has 4 layers.

• Examples of layers include the physical layer, data link layer, network layer, transport layer, and application layer.

Deadlock is a situation where two or more processes are unable to proceed because they are waiting for each other to release resources.

• Occurs in multi-threaded/multi-process environments

• Can lead to system freeze or crash

• Prevention techniques include resource ordering and timeouts

• Example: Process A holds resource X and waits for resource Y, while Process B holds resource Y and waits for resource X

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.

• Paging allows for efficient use of physical memory and reduces fragmentation.

• Segmentation allows for protection and sharing of memory between processes.

• Examples of operating s...read more

Reverse a linked list using iterative and recursive methods.

• Iterative method involves traversing the list and changing the pointers to reverse the order.

• Recursive method involves calling the function recursively on the next node and changing the pointers.

• Both methods have O(n) time complexity and O(1) space complexity.

• Example: 1->2->3->4->5 becomes 5->4->3->2->1.

Clone a linked list with a random pointer.

• Create a new node for each node in the original list.

• Use a hash table to map the original nodes to their clones.

• Iterate through the original list again and update the random pointers of the clone nodes.

The question asks to input an array and print the repeating characters.

• Iterate through the array and store each element in a hash table or dictionary.

• If an element already exists in the hash table, it is a repeating character.

• Print all the repeating characters found.

Program to find the second minimum in an array.

• Sort the array and return the second element.

• Initialize two variables to store minimum and second minimum values.

• Loop through the array and update the variables accordingly.

To find the longest palindrome in a given string.

• Iterate through the string and check for palindromes of odd and even lengths.

• Keep track of the longest palindrome found so far.

• Use two pointers to check if the substring is a palindrome.

• If the substring is a palindrome and its length is greater than the current longest palindrome, update the longest palindrome.

Find the next higher number with equal number of ones in binary representation.

• Convert input number to binary

• Count number of ones in binary representation

• Increment input number until binary representation has equal number of ones

• Convert incremented number to decimal

Find the duplicate number in an array of 10 numbers with only 2 steps.

• Use a hash set to keep track of visited numbers.

• Iterate through the array and check if the number is already in the set.

• If it is, then it is the duplicate number.

• If not, add it to the set.

• At the end, the duplicate number will be found.

Program to print elements of a linked list in reverse order using same single linked list

• Traverse the linked list and push each element onto a stack

• Pop elements from the stack and print them in reverse order

To check the occurrence and correctness of HTML tags, we can use various tools and techniques.

• One way is to use a browser's developer tools to inspect the HTML code and see the tags and their frequency.

• Another way is to use an online HTML validator tool that checks for correct syntax and tag usage.

• We can also use programming languages like Python to parse HTML and count the occurrence of each tag.

• Regular expressions ca...read more