Qualcomm Staff Engineer Interview Questions and Answers

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

I am a passionate software engineer with experience in developing web applications using various technologies.

• Experienced in developing web applications using HTML, CSS, JavaScript, and frameworks like React and Angular

• Proficient in backend development with Node.js and databases like MongoDB and MySQL

• Familiar with version control systems like Git and project management tools like Jira