200+ Qualcomm 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)

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

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.

Implement insertion sort algorithm on a singly linked list with integer values.

• Traverse the linked list and for each node, find its correct position in the sorted list.

• Remove the node from the original list and insert it at the correct position in the sorted list.

• Repeat this process until all nodes are sorted.

• Ensure the implementation is in-place, without using extra space.

• Handle edge cases like empty list or single node list.

Implement a Stack data structure using a Singly Linked List with operations in O(1) time.

• Create a class named Stack with getSize, isEmpty, push, pop, and getTop methods.

• Use a Singly Linked List to store the elements of the stack.

• Ensure each operation runs in O(1) time complexity.

• Handle cases where the stack is empty appropriately.

• Implement the logic for each query type as specified in the input and output sections.

Find the minimum number of fountains to activate to water the entire garden.

• Iterate through the array to find the coverage of each fountain.

• Keep track of the farthest coverage reached by activating fountains.

• Activate the fountain that covers the farthest point not yet covered.

• Repeat until the entire garden is watered.

Generate a rectangular pattern with outer rectangle filled with N and inner rectangles containing decreasing numbers.

• Create a 2-D array with dimensions based on input N

• Fill the outer rectangle with N and inner rectangles with decreasing numbers down to 1

• Adjust the values in the inner rectangles based on the layer number

• Return the generated pattern as a 2-D list/array

Given a rotated sorted array, find the index of a given integer 'K'.

• Use binary search to find the pivot point where the array is rotated.

• Based on the pivot point, perform binary search on the appropriate half of the array to find 'K'.

• Handle cases where 'K' is not present in the array by returning -1.

The number of ways to arrange sets of coloured balls in a line.

• The number of ways to arrange the red balls is the factorial of the number of red balls.

• The number of ways to arrange the blue balls is the factorial of the number of blue balls.

• The number of ways to arrange the green balls is the factorial of the number of green balls.

• To find the total number of arrangements, multiply the number of arrangements for each set.

Merge overlapping intervals and return sorted list of merged intervals.

• Iterate through intervals and merge overlapping ones

• Sort merged intervals based on starting times

• Handle edge cases like empty input or single interval

• Use a data structure like list or array to store merged intervals

Generate and print all prime numbers between 2 and N, inclusive.

• Iterate from 2 to N and check if each number is prime

• Use a helper function to determine if a number is prime

• Print each prime number on a new line

Min-Cut placement algorithm is used to place blocks on a given chip area.

• Min-Cut algorithm partitions the chip into two parts and minimizes the cut between them

• It is a graph-based algorithm that uses a flow network to represent the chip and its blocks

• The algorithm iteratively partitions the network until all blocks are placed

• Example: Placing logic gates on a microprocessor chip

Overlap-add method of convolution is implemented by dividing the input signal into overlapping segments and convolving each segment with a filter.

• Divide the input signal into overlapping segments

• Apply the filter to each segment

• Add the convolved segments together to get the output signal

• The length of each segment should be greater than or equal to the length of the filter

• The overlap between adjacent segments should be greater than or equal to the length of the filter minus one

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

Bellman Ford algorithm is used to find the shortest path in a graph with negative weights.

• Initialize distances from source to all vertices as infinity, and distance to source as 0.

• Relax all edges V-1 times to find shortest path.

• If any distance is updated in Vth iteration, then there is a negative weight cycle.

• Return the distance to destination vertex after V-1 iterations.

• Example: For the given graph, shortest path from vertex 1 to 3 is 1->2->3 with weight 1.

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

Parity is a method of error detection in digital communication. It involves adding an extra bit to a data stream to ensure even or odd number of 1s.

• Parity is used to detect errors in data transmission.

• It involves adding a parity bit to a data stream.

• The parity bit is set to 1 or 0 depending on whether the number of 1s in the data stream is even or odd.

• If an error occurs during transmission, the parity bit will be incorrect and the receiver can detect the error.

• Parity can be u...read more

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

Detect and remove loop in a singly linked list in place with O(n) time complexity and O(1) space complexity.

• Use Floyd's Tortoise and Hare algorithm to detect the loop in the linked list.

• Once the loop is detected, find the start of the loop using the algorithm.

• Adjust the pointers to remove the loop and return the modified linked list.

• Example: For input 5 2 and 1 2 3 4 5, the output should be 1 2 3 4 5.

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.

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

The minimum number of steps needed to find the value of an nth order polynomial is n+1.

• To find the value of a 1st order polynomial, we need 2 steps (1 multiplication and 1 addition).

• For an nth order polynomial, we need to compute n 1st order polynomials and perform n-1 additions.

• Therefore, the minimum number of steps is n+1.

• If parallel processing is allowed, we can compute the value of each 1st order polynomial simultaneously, reducing the time taken.

• In this case, the number ...read more

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

State diagram and clocked D-flipflop circuit for a 0110 sequence detector.

• The state diagram will have four states: S0, S1, S2, and S3.

• The circuit will have four D-flipflops, one for each state.

• The output of the circuit will be high when the sequence 0110 is detected.

• The clock signal will be used to synchronize the flipflops.

• The state diagram and circuit can be designed using software like Quartus or Xilinx.

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

The in-phase and quadrature components of a real pass-band signal can be obtained using a complex mixer.

• A complex mixer is used to convert the real pass-band signal to a complex baseband signal.

• The in-phase component is obtained by multiplying the pass-band signal with a local oscillator signal in-phase with the carrier frequency.

• The quadrature component is obtained by multiplying the pass-band signal with a local oscillator signal 90 degrees out of phase with the carrier fre...read more

The bit-rate for quantization of a band-limited signal can be obtained by considering the Nyquist-Shannon sampling theorem.

• The Nyquist-Shannon sampling theorem states that in order to accurately represent a band-limited signal, the sampling rate must be at least twice the highest frequency component of the signal.

• The bit-rate for quantization is determined by the number of bits used to represent each sample. It is typically calculated as the product of the sampling rate and t...read more

Moore state model outputs depend only on the current state, while Mealy state model outputs depend on both current state and inputs.

• Moore model: output is a function of current state only

• Mealy model: output is a function of current state and inputs

• Moore model has a separate output function, while Mealy model combines output and state transition functions

• Example: vending machine can be modeled using Mealy model as output depends on both current state and input (money inserted)...read more

Check if a given integer is a power of two or not.

• Check if the given integer is greater than 0.

• Check if the given integer has only one set bit (i.e., it is a power of 2).

• Return true if the above conditions are met, else return false.

Design a circuit to get an output of frequency f/3 from a clock waveform of frequency f.

• Use a counter to divide the frequency by 3

• Implement a flip-flop to toggle the output

• Use logic gates to control the counter and flip-flop

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

Interpolation in discrete-time domain involves estimating values between known data points.

• Interpolation is used to fill in missing data or estimate values between known data points.

• Common interpolation techniques include linear interpolation, polynomial interpolation, and spline interpolation.

• Linear interpolation calculates values along a straight line between two known data points.

• Polynomial interpolation uses a polynomial function to estimate values between data points.

• Spl...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

To optimize power usage/delay in AND gates, arrange inputs based on their capacitance and resistance.

• Arrange inputs with lower capacitance and resistance closer to the gate

• Inputs with higher capacitance and resistance should be placed farther away

• Consider the layout of the circuit and the routing of the wires

• Simulation tools can be used to determine optimal input arrangement

Answering a question on drawing CMOS circuit and W/L sizing for a given logic equation.

• Understand the logic equation and its truth table

• Use CMOS inverter and NAND gates to implement the logic

• Size the transistors based on their role in the circuit

• Check the circuit for correct functionality

• Examples: AND gate, OR gate, XOR gate

Draw output waveforms for a logic circuit given delays for gates and wires.

• Identify the logic gates and their delays

• Determine the propagation delay for each wire

• Use the delays to calculate the output waveform

• Draw the waveform using a timing diagram

Nyquist sampling frequency for unevenly distributed band-limited signal.

• Determine the highest frequency component in the signal

• Use Nyquist theorem to calculate the minimum sampling frequency

• Sampling frequency should be at least twice the highest frequency component

Modulation is the process of varying a carrier signal to transmit information. Different types include AM, FM, PM, and QAM.

• Modulation is used to transfer information by varying a high-frequency carrier signal.

• Amplitude Modulation (AM) varies the amplitude of the carrier signal to encode information.

• Frequency Modulation (FM) varies the frequency of the carrier signal to encode information.

• Phase Modulation (PM) varies the phase of the carrier signal to encode information.

• Quadra...read more

A circuit for a set of logic equations using PLA

• PLA stands for Programmable Logic Array

• PLA is a type of digital circuit used to implement combinational logic circuits

• The circuit consists of an AND array and an OR array

• Inputs are fed into the AND array and the outputs are fed into the OR array

• Example: A PLA circuit for a 2-input XOR gate would have 2 inputs, 2 AND gates, and 1 OR gate

Designing a memory organization based on size and block units.

• Determine the size of the memory and the size of each block unit

• Choose a suitable memory organization scheme such as direct mapping, associative mapping, or set-associative mapping

• Implement the chosen scheme and test for efficiency and accuracy

A random number generator circuit diagram can be created using a noise source and an amplifier.

• Use a noise source such as a Zener diode or a reverse-biased transistor

• Amplify the noise signal using an amplifier circuit

• Use a comparator to convert the analog signal to a digital signal

• Add a clock circuit to control the output frequency

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

Function to dynamically allocate memory and write data to a memory location, returning the address details.

• Use malloc() or calloc() to dynamically allocate memory

• Use memcpy() or strcpy() to write data to the allocated memory

• Return the address details where data is present

Volatile keyword prevents compiler optimization by telling the compiler that the variable's value can change unexpectedly.

• Volatile keyword is used to indicate that a variable may be changed unexpectedly, such as in the case of hardware registers.

• When initializing GPIO pins, using volatile keyword ensures that the compiler does not optimize away the initialization code.

• Without volatile keyword, the compiler may optimize out the GPIO initialization code if it thinks the value w...read more

Traverse a linked list based on input 0 or 1 to return decimal equivalent.

• Create a function that takes input 0 or 1 and traverses the linked list accordingly.

• For each node in the linked list, multiply the current decimal value by 2 and add the data of the node if input is 1.

• Return the final decimal value after traversing the linked list.

The choice of scheduling strategy in real-time operating systems depends on the system requirements and constraints.

• Priority-based scheduling is commonly used in real-time operating systems.

• Earliest Deadline First (EDF) scheduling is suitable for systems with strict deadlines.

• Rate Monotonic Scheduling (RMS) is appropriate for systems with periodic tasks.

• Shortest Job First (SJF) scheduling can be used for systems with non-periodic tasks.

• The choice of scheduling strategy should...read more

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

Different types of analog modulation schemes can be found in various communication systems.

• Analog modulation schemes are used in radio broadcasting, television transmission, and wireless communication.

• Some common types of analog modulation schemes include amplitude modulation (AM), frequency modulation (FM), and phase modulation (PM).

• AM is used in AM radio broadcasting, where the amplitude of the carrier signal is varied to transmit audio signals.

• FM is used in FM radio broadc...read more

Use a hash table to store the strings with their associated integers.

• Create a hash table with the integers as keys and the strings as values.

• Use a hash function to map the integers to their corresponding buckets in the table.

• To search for a string, compute the hash of its associated integer and look it up in the table.

Two modes of execution in operating systems are user mode and kernel mode.

• User mode is a restricted mode where user applications run.

• Kernel mode is a privileged mode where the operating system kernel runs.

• User mode has limited access to hardware and system resources.

• Kernel mode has full access to hardware and system resources.

• Switching between modes requires a system call or interrupt.

• Examples of system calls include opening a file or creating a process.

• Kernel mode is more po...read more

Linux kernel is popular for its open-source nature, stability, security, and flexibility. Compiling it allows customization and optimization.

• Linux kernel is widely used due to its open-source nature, allowing for customization and collaboration.

• It is known for its stability, security, and flexibility, making it a preferred choice for many developers and organizations.

• Compiling the Linux kernel involves configuring the kernel options, building the kernel image, and installing ...read more

Program with 2 threads printing even and odd numbers in sequence. How to make it SMP safe?

• Use mutex locks to ensure only one thread accesses the shared resource (the number to be printed) at a time

• Use condition variables to signal when it's safe for the other thread to access the shared resource

• Use atomic variables to ensure that the shared resource is accessed atomically

• Use thread-safe data structures to store the shared resource

• Use thread-local storage to avoid contention b...read more

Propagation delay is the time it takes for an electromagnetic wave to travel from one point to another.

• Propagation delay is determined by the distance between the two points and the speed of light.

• It is the time it takes for the wave to propagate through a medium or free space.

• Propagation delay can be calculated using the formula: delay = distance / speed of light.

• For example, if the distance between two points is 100 meters, and the speed of light is 3 x 10^8 meters per seco...read more

When a null pointer is dereferenced, it leads to a segmentation fault or access violation, causing the program to crash.

• Dereferencing a null pointer means trying to access the memory location pointed by the null pointer.

• This results in a segmentation fault or access violation, as the null pointer does not point to a valid memory address.

• The operating system detects the illegal memory access and terminates the program to prevent further issues.

• The stack and memory remain unaff...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

The y c malloc function returns memory from the heap while y stack operates in reverse.

• The y c malloc function is used to allocate memory dynamically from the heap.

• The y stack operates in reverse, meaning the last item pushed onto the stack is the first item popped off.

• This can cause issues if the programmer is not careful with memory allocation and stack usage.

A Schmitt trigger/inverter is a circuit that converts a noisy input signal into a clean digital output signal.

• It has two threshold voltage levels: a high threshold and a low threshold

• The output of the circuit changes state only when the input voltage crosses one of the threshold levels

• It is commonly used in digital circuits to clean up noisy signals and to provide hysteresis

• Examples include debouncing switches, signal conditioning, and waveform shaping

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

Initialize and control GPIO using HAL functions in embedded systems.

• Use HAL_GPIO_Init() function to initialize GPIO pins

• Use HAL_GPIO_WritePin() function to set or clear GPIO status

• Example: HAL_GPIO_Init(&GPIO_InitStruct)

• Example: HAL_GPIO_WritePin(GPIOx, GPIO_PIN_x, GPIO_PIN_SET)

The number of parallelograms in a grid of mxn parallel lines can be calculated using a formula involving combinations.

• The formula to calculate the number of parallelograms is (m * (m + 1) * n * (n + 1)) / 4

• For example, in a 2x3 grid, there are (2 * 3 * 3 * 4) / 4 = 18 parallelograms

• The formula is derived by considering all possible combinations of 4 points on the grid to form a parallelogram

Negating alternate samples in time domain results in spectral inversion.

• Negating alternate samples in time domain is equivalent to multiplying the signal by a square wave with alternating values of +1 and -1.

• This multiplication in time domain results in spectral convolution in frequency domain.

• The frequency spectrum is inverted around the Nyquist frequency due to the spectral convolution.

• This technique is used in some audio effects like flangers and phasers.

• It can also be use...read more

VSWR stands for Voltage Standing Wave Ratio. It is a measure of how well a transmission line is matched to the impedance of the connected devices.

• VSWR is a ratio of the maximum voltage to the minimum voltage along a transmission line.

• It is used to measure the efficiency of power transfer and the impedance matching in RF systems.

• A lower VSWR indicates better impedance matching and less power loss.

• VSWR is important in RF systems to prevent signal reflections, which can degrade ...read more

A standing wave in a transmission line is a wave that appears to be stationary, resulting from the interference of two waves traveling in opposite directions.

• A standing wave is formed when a wave traveling in one direction reflects back upon encountering an impedance mismatch in the transmission line.

• The interference between the incident and reflected waves creates regions of constructive and destructive interference, resulting in nodes and antinodes along the transmission li...read more

To construct a 4x16 decoder from 2x4 decoders with enable pins, you can use the enable pins of the 2x4 decoders to control the output of the 4x16 decoder.

• Use one 2x4 decoder to decode the first 2 bits of the input and the other 2x4 decoder to decode the last 2 bits of the input.

• Connect the enable pins of the 2x4 decoders to the same control signal, which will act as the enable pin for the 4x16 decoder.

• Combine the outputs of the 2x4 decoders to form the 16 outputs of the 4x16 ...read more

My LAB has a star topology because it provides centralized control and easy troubleshooting.

• Star topology has a central hub that connects all devices

• All communication goes through the hub

• Easy to add or remove devices without affecting the rest of the network

• Commonly used in LANs

• Examples: Home networks, small businesses

Histogram equalization is a technique to enhance the contrast of an image by redistributing pixel intensities.

• Histogram equalization stretches the histogram of an image to cover the entire range of pixel values.

• It increases the dynamic range of an image, making it visually more appealing.

• It improves the visibility of details in both dark and bright regions of an image.

• Histogram equalization can be used to enhance images with low contrast or uneven lighting conditions.

• For exam...read more

Feasibility, impact, and risk are key factors in determining the risk value of an attack.

• Feasibility refers to how likely an attack is to occur based on the resources and knowledge required.

• Impact measures the potential damage or consequences of the attack if successful.

• Risk is the combination of feasibility and impact, representing the likelihood and severity of the attack.

• To determine risk value, assess the feasibility of the attack based on available vulnerabilities, then ...read more

Distributed cybersecurity activities in ISO21434 refer to the implementation of cybersecurity measures across multiple components or systems within a network.

• Distributed cybersecurity activities involve securing various interconnected components or systems within a network.

• This includes implementing security measures such as firewalls, encryption, access controls, and intrusion detection systems.

• The goal is to protect the entire network from cyber threats by addressing vulner...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.

The product of N normal RVs is a non-central chi-squared distribution with N degrees of freedom.

• The distribution is non-central chi-squared with N degrees of freedom

• The non-centrality parameter is the product of the means of the RVs

• The variance of the distribution is the product of the variances of the RVs

• This distribution is commonly used in signal processing and communication systems

Sort a linked list with minimum time complexity

• Use merge sort or quick sort for O(n log n) time complexity

• Implement the sorting algorithm recursively

• Use a temporary linked list to merge the sorted sub-lists

• Consider edge cases like empty list or list with only one element

Code to print all connected components in a graph.

• Implement Depth First Search (DFS) algorithm to traverse the graph.

• Maintain a visited array to keep track of visited nodes.

• For each unvisited node, perform DFS and add all visited nodes to a connected component.

• Repeat until all nodes are visited.

• Print all connected components.

Endianess refers to the order in which bytes are stored in memory. Little endian stores the least significant byte first.

• Check the byte order of a multi-byte integer value

• Use a test value with known byte order to determine the system's endianess

• Check the system's documentation or specifications

• Use a code snippet to determine the endianess

Amplitude modulation (AM) and frequency modulation (FM) waveforms can be represented graphically.

• AM modulation: The amplitude of the carrier signal is varied in proportion to the amplitude of the modulating signal.

• FM modulation: The frequency of the carrier signal is varied in proportion to the amplitude of the modulating signal.

• Waveforms can be drawn to show the variations in amplitude or frequency over time.

• AM waveform will have varying amplitudes while FM waveform will hav...read more

Function to return Fibonacci series of N elements

• Create an array to store the series

• Use a loop to generate the series

• Return the array

Inter-process communication mechanisms like pipes, sockets, message queues, shared memory can be used to call a function from one user process to another.

• Use pipes to establish a unidirectional communication channel between two processes.

• Use sockets to establish a bidirectional communication channel between two processes.

• Use message queues to send messages between processes.

• Use shared memory to share data between processes.

• Remote Procedure Call (RPC) can also be used to call ...read more

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

Maximal Ratio Combining (MRC) is a technique used in MIMO systems to improve signal quality by combining multiple received signals.

• MRC combines the received signals from multiple antennas to maximize the signal-to-noise ratio (SNR)

• Quantization noise power refers to the noise introduced during the process of converting analog signals to digital signals

• In MIMO systems, MRC can be used to mitigate the effects of quantization noise

• MRC calculates the weights for each received sign...read more

Function pointers can be shared across processes using inter-process communication mechanisms like shared memory, pipes, sockets, etc.

• Function pointers can be stored in shared memory regions that are accessible by multiple processes.

• Processes can communicate with each other using pipes or sockets and pass function pointers as arguments.

• Remote Procedure Call (RPC) mechanisms can also be used to share function pointers across processes.

• Message Passing Interface (MPI) is another...read more

Program to find length of bits assigned in memory using recursion.

• Define a recursive function to count the bits in memory

• Base case: if input is 0, return 0

• Recursive case: return 1 + function(input / 2)

Program to find the sum of all the digits in a number.

• Iterate through each digit in the number and add them together.

• Convert the number to a string to easily access each digit.

• Use modulo operator to extract each digit from the number.

• Handle negative numbers by taking the absolute value before processing.

Check if a linked list is circular, if not reverse it.

• Create two pointers, one moving at double the speed of the other to detect a cycle

• If a cycle is detected, the list is circular. If not, reverse the list by changing the pointers' directions

RTOS stands for Real-Time Operating System. It is designed to handle time-sensitive tasks and provide deterministic behavior.

• RTOS is optimized for real-time applications that require precise timing and responsiveness.

• Unlike general-purpose operating systems, RTOS provides deterministic behavior, meaning tasks are guaranteed to be completed within a specific time frame.

• RTOS typically uses priority-based scheduling algorithms to ensure critical tasks are executed on time.

• Exampl...read more

Pdf of sum and max of two iid uniform rvs in the range 0 to 1

• The sum of two uniform random variables is a triangular distribution

• The maximum of two uniform random variables is also a uniform distribution

• The joint pdf can be derived using convolution and differentiation

• The resulting pdf will have piecewise functions

An SRAM cell is a type of memory cell that stores a single bit of data using two cross-coupled inverters.

• Consists of two inverters connected in a feedback loop

• Has two stable states, representing 0 and 1

• Uses two access transistors to read and write data

• Commonly used in cache memory and microprocessors

Demodulating a QAM signal involves separating the amplitude and phase components to recover the original data.

• QAM signals combine amplitude and phase modulation

• Demodulation involves separating the amplitude and phase components

• Techniques like coherent demodulation and quadrature demodulation are used

• Coherent demodulation uses a local oscillator to recover the phase component

• Quadrature demodulation separates the in-phase and quadrature components

The impulse response of a system can be found by applying a short impulse input and measuring the output.

• Apply a short impulse input to the system

• Measure the output of the system

• Take the Fourier transform of the input and output signals

• Divide the output Fourier transform by the input Fourier transform to get the transfer function

• Take the inverse Fourier transform of the transfer function to get the impulse response

A transmitter and receiver are essential components of a communication system.

• Transmitter converts information into a suitable form for transmission.

• Receiver receives the transmitted signal and converts it back into the original form.

• Transmitter typically includes a modulator, power amplifier, and antenna.

• Receiver typically includes an antenna, demodulator, and audio or video output.

• Example: In a radio communication system, the transmitter converts audio signals into radio wa...read more

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