40+ Envision Computer Training Institute Interview Questions and Answers

Four people with different crossing times need to cross a bridge with a torch. Only two can cross at a time. What is the least time taken?

• Person A and B cross first, taking 2 minutes

• A goes back with the torch, taking 1 minute

• C and D cross together, taking 10 minutes

• B goes back with the torch, taking 2 minutes

• A and B cross together, taking 2 minutes

• Total time taken is 17 minutes

C program to find P and Q (P>Q) such that A[P] - A[Q] is maximum

• Iterate through array and keep track of maximum difference and corresponding indices

• Initialize P and Q to first two elements and update as necessary

• Time complexity: O(n)

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

• Deadlocks occur when two or more processes are blocked and unable to continue executing.

• To detect a deadlock, look for circular wait, hold and wait, no preemption, and mutual exclusion.

• Examples of deadlocks include a printer that is waiting for a user to replace the paper tray, or two trains that are stuck on the same track waiting for each ...read more

OS functions include managing hardware resources, providing user interface, and running applications.

• Managing hardware resources such as CPU, memory, and storage

• Providing user interface for interaction with the computer

• Running applications and managing processes

• Managing file systems and data storage

• Providing security and access control

• Managing network connections and communication

• Performing system updates and maintenance

• Handling errors and system crashes

• Virtualization and con...read more

The question asks to fill the blanks in a pyramid where each number is the sum of the numbers in the bottom two cells.

• Start from the bottom row and work your way up, calculating the sum of the numbers in the bottom two cells for each blank space.

• Use a loop to iterate through each row and column of the pyramid.

• Store the calculated sum in the corresponding blank space.

• Repeat the process until all the blanks are filled.

Scheduling is the process of allocating resources to tasks based on priority and availability.

• Different types of scheduling include: preemptive and non-preemptive scheduling, round-robin scheduling, priority scheduling, and deadline scheduling.

• Preemptive scheduling allows higher priority tasks to interrupt lower priority tasks, while non-preemptive scheduling does not.

• Round-robin scheduling allocates a fixed time slice to each task in a cyclic manner.

• Priority scheduling assig...read more

Multi-core processors provide faster and more efficient computing.

• Improved performance and speed

• Ability to handle multiple tasks simultaneously

• Reduced power consumption

• Better multitasking capabilities

• Enhanced user experience

• Examples: Intel Core i7, AMD Ryzen 9

Explain Big O notation

• Big O notation is used to describe the time complexity of an algorithm

• It helps us understand how the algorithm's performance changes with input size

• O(1) means constant time, O(n) means linear time, O(n^2) means quadratic time

• We want algorithms with lower Big O values for better performance

Task is a unit of work, process is an instance of a program, and thread is a subset of a process.

• Task is a single unit of work that needs to be completed.

• Process is an instance of a program that is being executed.

• Thread is a subset of a process that can run concurrently with other threads.

• A process can have multiple threads, but a thread can only belong to one process.

• Threads share the same memory space, while processes have their own memory space.

• Threads are lightweight comp...read more

Multi-threading, multi-processing and multi-tasking are different ways of achieving parallelism in computing.

• Multi-threading is a technique of dividing a single process into multiple threads that can run concurrently.

• Multi-processing is a technique of dividing a single process into multiple processes that can run concurrently.

• Multi-tasking is a technique of running multiple processes or tasks concurrently on a single processor.

• Multi-threading and multi-processing are used to ...read more

To delete a node from a linked list when only given a reference to the node, we can copy the data of the next node to the given node and delete the next node.

• Copy the data of the next node to the given node

• Update the next pointer of the given node to skip the next node

• Delete the next node

I am open to relocation based on the job opportunity and growth prospects.

• Open to relocation for the right opportunity

• Willing to move for career growth

• Flexible with location based on job requirements

Use bitwise operations to find the sum of two numbers without using mathematical operators.

• Use bitwise XOR to find the sum of two numbers without carrying.

• Use bitwise AND and left shift to find the carry.

• Repeat the process until there is no carry left.

Moore's Law is the observation that the number of transistors in a dense integrated circuit doubles about every two years.

• Named after Intel co-founder Gordon Moore

• First stated in 1965

• Has been a driving force behind technological advancements

• Predicts exponential growth in computing power

• Has been challenged in recent years due to physical limitations

Static, volatile, const are C keywords used to define properties of variables.

• Static: used to define a variable that retains its value between function calls

• Volatile: used to indicate that a variable's value may change unexpectedly, e.g. in an interrupt

• Const: used to define a variable whose value cannot be changed once initialized

A process is an instance of a program while a thread is a subset of a process.

• A process has its own memory space while threads share memory space

• Processes are heavyweight while threads are lightweight

• Processes communicate through inter-process communication while threads communicate through shared memory

• Examples of processes include web browsers, text editors, etc. while examples of threads include GUI updates, background tasks, etc.

To separate 5 heads and 2 tails into two groups with equal number of tails, we can divide them as follows:

• Group 1: 1 head and 1 tail

• Group 2: 4 heads and 1 tail

Pseudo code to remove a node from a linked list

• Find the node to be removed

• Update the previous node's next pointer to point to the next node

• Free the memory occupied by the removed node

AC and DC are two types of electrical current with different characteristics.

• AC stands for Alternating Current, while DC stands for Direct Current.

• AC periodically changes direction, while DC flows in one direction.

• AC is commonly used in household electrical systems, while DC is used in batteries and electronic devices.

• AC can be easily transformed to different voltage levels using transformers, while DC requires converters or inverters for voltage transformation.

• AC is more eff...read more

Qualcomm is a semiconductor and telecommunications equipment company based in San Diego, California.

• Qualcomm is a leading provider of wireless technology and services.

• They are known for their Snapdragon processors used in smartphones and other devices.

• Qualcomm has been involved in several legal disputes with Apple and other companies over patent infringement.

• They also have a strong presence in the development of 5G technology.

• Qualcomm has a diverse portfolio of products and s...read more

ISR stands for Interrupt Service Routine. It is managed by prioritizing interrupts and handling them in a timely manner.

• Prioritize interrupts based on their importance

• Handle interrupts in a timely manner to prevent delays in the system

• Ensure that the ISR does not interfere with the normal flow of the program

• Test the ISR thoroughly to ensure that it works as expected

• Use appropriate tools and techniques to debug any issues that arise

I will solve disputes by promoting open communication, active listening, and finding mutually beneficial solutions.

• Encourage open and honest communication between parties involved

• Actively listen to each party's concerns and perspectives

• Identify common goals and interests to find mutually beneficial solutions

• Mediate discussions and facilitate negotiations if necessary

• Document agreements and ensure follow-up to prevent future disputes

Quick sort has an average and worst-case time complexity of O(n log n).

• Quick sort is a divide-and-conquer algorithm.

• It selects a pivot element and partitions the array around the pivot.

• The average and worst-case time complexity is O(n log n).

• However, in the worst-case scenario, it can have a time complexity of O(n^2).

Qualcomm is a leading semiconductor and telecommunications equipment company.

• Qualcomm is known for its expertise in wireless technologies and mobile chipsets.

• They have developed popular Snapdragon processors used in smartphones and tablets.

• Qualcomm has made significant contributions to the advancement of 5G technology.

• The company has a strong patent portfolio and is involved in licensing its technology to other manufacturers.

• Qualcomm has faced legal challenges and regulatory ...read more

An alternator and generator are devices that convert mechanical energy into electrical energy.

• Both alternators and generators are used to generate electricity.

• They work on the principle of electromagnetic induction.

• Alternators are commonly used in modern vehicles to charge the battery and power the electrical systems.

• Generators are often used as backup power sources during power outages.

• Examples of alternators include those found in cars, motorcycles, and airplanes.

• Examples o...read more

Types of caching mechanisms include browser caching, server-side caching, and content delivery network (CDN) caching.

• Browser caching: storing web page resources locally on a user's device to reduce load times on subsequent visits.

• Server-side caching: storing data in memory on the server to reduce the need to fetch data from the database repeatedly.

• Content Delivery Network (CDN) caching: caching content on servers distributed geographically to reduce latency and improve perfor...read more

Mutex is a synchronization mechanism used to prevent multiple threads from accessing shared resources simultaneously.

• Mutex stands for mutual exclusion.

• It is used to protect shared resources from race conditions.

• Mutex provides exclusive access to a shared resource.

• It is used in multi-threaded programming.

• Mutex can be implemented using locks or semaphores.

Fill the cells in the pyramid

• The pyramid is a pattern of numbers or characters arranged in a triangular shape

• Each row of the pyramid has one more cell than the previous row

• Start filling the pyramid from the top and move downwards

• The cells can be filled with any desired numbers or characters

To delete a node in a linked list, we need to adjust the pointers of the previous node and the next node.

• Find the node to be deleted

• Adjust the pointers of the previous node and the next node

• Free the memory of the deleted node

Insertion in binary search trees involves finding the appropriate position for a new node based on its value.

• Start at the root node and compare the value of the new node with the current node.

• If the new node's value is less than the current node, move to the left child node.

• If the new node's value is greater than the current node, move to the right child node.

• Repeat the comparison and movement until reaching a leaf node or a null position.

• Insert the new node at the null posit...read more

Physical memory refers to the actual RAM installed in a computer, while virtual memory is a memory management technique that uses disk space as an extension of RAM.

• Physical memory is the actual hardware component where data is stored temporarily for quick access by the CPU.

• Virtual memory is a memory management technique that allows the operating system to use disk space as an extension of physical memory.

• Physical memory is faster than virtual memory because it is directly acc...read more

SHA Algorithm is a cryptographic hash function that takes an input and produces a fixed-size output.

• SHA stands for Secure Hash Algorithm.

• It is widely used in various security applications and protocols.

• SHA-1, SHA-256, SHA-384, and SHA-512 are common variants of SHA.

• It generates a unique hash value for each unique input.

• The output is a fixed length, regardless of the input size.

• SHA is used for data integrity, password hashing, digital signatures, etc.

Design a traffic signal system

• Identify the number of lanes and directions

• Determine the duration of each signal phase

• Consider pedestrian crossings and emergency vehicle prioritization

• Implement sensors to detect traffic flow

• Use machine learning algorithms to optimize signal timing

Register classes in C are used to define new data types. MMU is a hardware component that maps virtual addresses to physical addresses.

• Register classes in C are used to define new data types with specific storage classes.

• MMU stands for Memory Management Unit and is a hardware component that maps virtual addresses to physical addresses.

• The MMU is responsible for managing the translation of virtual addresses to physical addresses, allowing programs to access memory without know...read more

Code for scheduling in C

• Define a struct for the task with fields like start time, end time, priority, etc.

• Create an array of tasks and sort them based on priority and start time

• Implement a scheduling algorithm like Round Robin or Priority Scheduling

• Use system calls like fork() and exec() to create and execute processes

• Implement synchronization mechanisms like semaphores or mutexes to avoid race conditions

Volatile keyword in Java is used to indicate that a variable's value will be modified by multiple threads.

• Volatile keyword ensures visibility of changes made by one thread to other threads.

• It prevents compiler optimizations that could reorder code and cause unexpected behavior in multi-threaded environments.

• Volatile keyword is used for variables accessed by multiple threads without synchronization.

• Example: 'volatile int count = 0;'

Union is a data structure that allows storing different data types in the same memory location, while structure is a data structure that allows storing different data types in a single unit.

• Union uses the same memory location for all its members, while structure allocates separate memory for each member.

• In a union, only one member can be accessed at a time, while in a structure, all members can be accessed simultaneously.

• Example: Union can be used to represent a variable that...read more

Detect endianness using C program

• Use a union to create a variable with a known value

• Check the value of the first byte to determine endianness

• Big endian systems store the most significant byte first

• Little endian systems store the least significant byte first

• Example: union { int i; char c; } u; u.i = 1; if (u.c == 1) { /* Little endian */ } else { /* Big endian */ }

Rotate a linked list with a given k size

• Create a function to rotate a linked list by k nodes

• Use two pointers to find the kth node from the end and the end node

• Adjust the pointers to rotate the linked list accordingly

Circular buffer is a data structure that uses a fixed-size buffer as if it were connected end-to-end.

• Circular buffer is also known as a ring buffer or cyclic buffer.

• It is often used in computer programming to implement a queue that needs constant time for adding or removing elements.

• When the buffer is full, new data overwrites the oldest data in a circular fashion.

• Circular buffers are efficient for streaming data applications where the data is continuously produced and consum...read more