Lam Research Sdet (Software Development Engineer in Test) Interview Questions and Answers

malloc is a function in C that dynamically allocates memory on the heap. It is used to allocate memory for variables or data structures.

• malloc is used in C programming language.

• It is used to allocate memory on the heap.

• malloc is different from 'new' in C++ as it does not call constructors for objects.

C++ is a general-purpose programming language while Objective C is a superset of C used for iOS and macOS development.

• C++ is widely used for developing applications, games, and system software.

• Objective C is mainly used for iOS and macOS development.

• C++ supports both procedural and object-oriented programming paradigms.

• Objective C is an object-oriented language with dynamic runtime features.

• C++ has a larger community a...read more

Class container is a class that holds objects of other classes, while class composition is a way to combine multiple classes to create a new class.

• Class container holds objects of other classes, acting as a collection or container.

• Class composition combines multiple classes to create a new class with its own behavior and attributes.

• In class container, the objects are typically stored in a data structure like an array o...read more

Divide the horses into groups of 5 and race them. Take the top 2 from each race and race them again. Finally, race the top 2 horses to determine the top 3.

• Divide the horses into 3 groups of 5 and race them.

• Take the top 2 horses from each race and race them again.

• Finally, race the top 2 horses to determine the top 3.

Developing a real-time data processing system for a high-traffic e-commerce website

• Implemented a distributed system architecture to handle large volumes of data

• Optimized algorithms for efficient data processing and storage

• Utilized caching mechanisms to improve system performance

• Worked closely with cross-functional teams to troubleshoot and resolve issues

• Example: Successfully reduced data processing time by 50% by imple...read more

The width of a tree is the maximum number of nodes at any level in the tree.

• To calculate the width of a tree, we can perform a level order traversal and keep track of the maximum number of nodes at any level.

• We can use a queue data structure to perform the level order traversal.

• At each level, we count the number of nodes in the queue and update the maximum width if necessary.

Locate sum of 2 numbers in a linear array (unsorted and sorted) and their complexities

• For unsorted array, use nested loops to compare each element with every other element until the sum is found

• For sorted array, use two pointers approach starting from the beginning and end of the array and move them towards each other until the sum is found

• Complexity for unsorted array is O(n^2) and for sorted array is O(n)

Pointers are used to manipulate memory addresses and values in C++. Increment/decrement, address of and value at operators are commonly used.

• Incrementing a pointer moves it to the next memory location of the same data type

• Decrementing a pointer moves it to the previous memory location of the same data type

• The address of operator (&) returns the memory address of a variable

• The value at operator (*) returns the value sto...read more

There are multiple combinations of 8-bit and 16-bit signed numbers. How many such combinations are possible?

• There are 2^8 (256) possible combinations of 8-bit signed numbers.

• There are 2^16 (65,536) possible combinations of 16-bit signed numbers.

• To find the total number of combinations, we can add the number of combinations of 8-bit and 16-bit signed numbers.

• Therefore, the total number of possible combinations is 256 + ...read more

Find duplicates in an array of elements in 0(n) time and 0(1) space.

• Use the property of inputs to your advantage

• Iterate through the array and mark elements as negative

• If an element is already negative, it is a duplicate

• Return all the negative elements as duplicates

Generate all combinations of digits from an array, allowing and disallowing repetition.

• Use recursion or backtracking to generate combinations.

• For repetition allowed: e.g., arr={1,2}, combinations are 11, 12, 21, 22.

• For repetition not allowed: e.g., arr={1,2,3}, combinations are 123, 132, 213, 231, 312, 321.

• Utilize a set to track used digits when repetition is not allowed.

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

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 ...read more

I developed a mobile app for tracking daily water intake and hydration levels.

• Researched best practices for hydration tracking

• Designed user-friendly interface for inputting water intake

• Implemented data visualization for tracking hydration levels

• Tested app with focus groups for feedback

• Continuously updated app based on user suggestions

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 h...read more

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 f...read more