Qualcomm SDE 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

Seeking new challenges and opportunities for growth.

• Looking for a more challenging role to further develop my skills

• Interested in exploring new technologies and industries

• Seeking better career advancement opportunities

• Want to work in a more collaborative team environment

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

To determine if a point is inside or outside a rectangle, we check if the point's coordinates fall within the rectangle's boundaries.

• Check if the point's x-coordinate is greater than the left edge of the rectangle

• Check if the point's x-coordinate is less than the right edge of the rectangle

• Check if the point's y-coordinate is greater than the top edge of the rectangle

• Check if the point's y-coordinate is less than the b...read more

To find line that divides rectangle into 2 equal halves through a point inside it.

• Find the center of the rectangle

• Draw a line from the center to the given point

• Extend the line to the opposite side of the rectangle

• The extended line will divide the rectangle into 2 equal halves

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.

Design logical circuits for arithmetic circuits in a blackbox.

• Understand the functionality of the arithmetic circuits in the blackbox.

• Identify the inputs and outputs of the blackbox.

• Design logical circuits using logic gates to replicate the arithmetic operations.

• Test the logical circuits to ensure they produce the same outputs as the arithmetic circuits.

Recursion in embedded C-code allows a function to call itself, useful for repetitive tasks or complex algorithms.

• Ensure proper base case to avoid infinite recursion

• Use stack space efficiently as embedded systems have limited resources

• Avoid recursive functions with deep call stacks to prevent stack overflow

• Example: Recursive function to calculate factorial of a number