Infinx Software Developer Interview Questions and Answers

Return all root to leaf node paths in a binary tree with row, col and value.

• Traverse the binary tree recursively and keep track of the current path.

• When a leaf node is reached, add the path to the result array.

• Include row, col and value of each node in the path.

• Use an array of strings to store the paths.

To get max value from a stack in O(1), maintain a separate stack to keep track of maximum values.

• Create a separate stack to keep track of maximum values

• Push the maximum value onto the stack whenever a new maximum is encountered

• Pop the maximum value stack whenever the top element of the main stack is popped

• Return the top element of the maximum value stack to get the maximum value in O(1)

To get max element from a queue in O(1) time complexity

• Maintain a separate variable to keep track of the maximum element in the queue

• Update the maximum element variable whenever a new element is added or removed from the queue

• Return the maximum element variable when getMax() function is called

Find the Next Greatest Element to the right for each element in an array of strings.

• Iterate through the array from right to left

• Use a stack to keep track of elements

• Pop elements from stack until a greater element is found

• If no greater element is found, assign -1

• Return the result array

To remove unnecessary parenthesis from an expression, we need to apply a set of rules to identify and eliminate them.

• Identify and remove parenthesis around single variables or constants

• Identify and remove parenthesis around expressions with only one operator

• Identify and remove parenthesis around expressions with operators of equal precedence

• Identify and remove parenthesis around expressions with operators of different ...read more

Find the maximum product of three integers in an array.

• Sort the array in descending order.

• Check the product of the first three numbers and the product of the first and last two numbers.

• Return the maximum of the two products.

Find length of longest consecutive sub array forming an AP from given array of integers.

• Sort the array in ascending order

• Iterate through the array and find the longest consecutive sub array forming an AP

• Use a variable to keep track of the length of the current consecutive sub array forming an AP

• Use another variable to keep track of the length of the longest consecutive sub array forming an AP seen so far

Operating on images in parallel involves dividing the image into smaller parts and processing them simultaneously.

• Divide the image into smaller parts using techniques like tiling or splitting

• Use parallel processing techniques like multi-threading or GPU acceleration

• Combine the processed parts to form the final image

• Examples: image segmentation, object detection, image enhancement

Hardware engines support parallelism through multiple cores and threads.

• Hardware engines can have multiple cores and threads to execute tasks simultaneously.

• Parallelism can improve performance and efficiency in hardware-based tasks.

• Examples include GPUs, FPGAs, and ASICs that have parallel processing capabilities.

• Hardware parallelism can also be achieved through distributed computing and clustering.

• Programming language...read more

Modern OSes support parallelism through multi-core processors and threading.

• Modern OSes like Windows, macOS, and Linux support parallelism through multi-core processors and threading.

• Parallelism can be achieved through processes or threads.

• Parallelism can improve performance and efficiency of software.

• Examples of parallel programming frameworks include OpenMP and MPI.

Memory protection is a feature of an operating system that prevents unauthorized access to memory locations.

• Memory protection is achieved through the use of memory management units (MMUs) and virtual memory.

• MMUs map virtual addresses to physical addresses and enforce access permissions.

• Virtual memory allows the OS to allocate memory to processes in a way that isolates them from each other.

• Examples of memory protection ...read more

To speed up multiplication of small integers in an array, we can use bitwise operations and parallel processing.

• Use bitwise operations like shifting and ANDing to perform multiplication faster.

• Divide the array into smaller chunks and perform multiplication in parallel using multi-threading or SIMD instructions.

• Use lookup tables for frequently used values to avoid repeated calculations.

• Use compiler optimizations like lo...read more

Design a data structure for excel spreadsheet

• Use a 2D array to store cell values

• Implement formulas using a stack

• Include formatting options for cells

Insertion sort and quicksort are sorting algorithms used to sort arrays of data.

• Insertion sort: iterates through the array and inserts each element into its proper position.

• Quicksort: selects a pivot element and partitions the array into two sub-arrays, one with elements less than the pivot and one with elements greater than the pivot.

• Insertion sort is best for small arrays, while quicksort is best for large arrays.

• Bot...read more

Merge two sorted linked lists using recursion

• Create a recursive function that compares the first nodes of both lists

• Set the smaller node as the head of the merged list and call the function again with the next node of the smaller list

• Base case: if one list is empty, return the other list

• Return the merged list

Given an integer, determine which byte is zero.

• Convert the integer to a byte array using bitwise operations.

• Iterate through the byte array and check for a zero value.

• Return the index of the zero byte.

• Consider endianness when converting to byte array.

To check endianness, create a 4-byte integer with a known value and check the byte order.

• Create a 4-byte integer with a known value

• Check the value of the first byte to determine endianness

• If the first byte is the least significant, the machine is little endian

• If the first byte is the most significant, the machine is big endian

Static objects can be used to print something before main() execution.

• Static objects are initialized before main() execution

• They can be used to print something before main()

• Example: static int x = printf("Hello World!");

• Output: Hello World! will be printed before main() execution

Static variables are allocated memory in the data segment of the program's memory space.

• Static variables have a fixed memory location throughout the program's execution.

• They are initialized to zero by default.

• If initialized explicitly, they are stored in the data segment.

• Static variables can be accessed by any function in the program.

Finding space and time complexity of a recursive function.

• Space complexity is the amount of memory used by the function.

• Time complexity is the amount of time taken by the function to execute.

• Recursive functions have higher space complexity due to the call stack.

• Time complexity can be calculated using Big O notation.

• Examples of recursive functions include factorial and Fibonacci sequence.

Diamond hierarchy problem is a problem in object-oriented programming where a class inherits from multiple classes in a diamond-shaped hierarchy.

• Occurs when a class inherits from two classes that share a common base class

• Can lead to ambiguity in method calls and data members

• Solved using virtual inheritance or by using interfaces

Find the minimum and maximum values in an array in a single traversal.

• Initialize min and max variables with the first element of the array

• Iterate through the array and update min and max if a smaller or larger value is found

• Return the min and max values

The maximum number of squares on a chessboard is 64.

• The chessboard has 64 squares in total.

• The number of squares on a chessboard can be calculated using the formula n^2, where n is the number of rows or columns.

• In this case, n = 8 (8 rows and 8 columns), so the maximum number of squares is 8^2 = 64.

C++ is a programming language. Deep copy creates a new object and copies all values, while shallow copy creates a reference to the original object.

• C++ is a general-purpose programming language

• Deep copy creates a new object with its own copy of the data

• Shallow copy creates a reference to the original object

• Deep copy is safer but can be slower and consume more memory

• Shallow copy is faster but can lead to unexpected behav

Pre initialization refers to the process of initializing variables or objects before they are used in a program.

• Pre initialization helps avoid errors or unexpected behavior caused by using uninitialized variables.

• It is a good practice to pre initialize variables with default values.

• Pre initialization can be done using constructors, default values, or initialization blocks.

• Example: int count = 0; initializes the variabl

Reverse a linked list with and without using Recursion

• Iterative approach: Use three pointers to reverse the links between nodes

• Recursive approach: Recursively reverse the rest of the list and then fix the links

Polymorphism refers to the ability of an object to take on many forms. The diamond problem occurs in multiple inheritance.

• Polymorphism can be achieved through method overloading and method overriding.

• Method overloading allows multiple methods with the same name but different parameters.

• Method overriding occurs when a subclass provides a specific implementation of a method already defined in its superclass.

• The diamond p...read more

The program should differentiate between integers and characters when using the assignment operator (=).

• Check the data type of the variable before assigning a value.

• Use conditional statements to perform different actions based on the data type.

• For integers, assign the value directly. For characters, convert the character to its ASCII value and assign it.

Sort an array by moving all zeroes to the end.

• Iterate through the array and move all non-zero elements to the front.

• Count the number of zeroes encountered and append them at the end of the array.

• Use two pointers to swap elements and maintain the order.

The number of VTables created in a class hierarchy depends on the number of virtual functions and the number of derived classes.

• VTables are used in object-oriented programming languages to implement dynamic dispatch.

• Each class with at least one virtual function has its own VTable.

• Derived classes inherit the VTable of their base class and add their own entries for any additional virtual functions.

• The total number of VTa...read more

List is preferred when frequent insertion and deletion is required. Vector is preferred when random access is required.

• List is implemented as a doubly-linked list, allowing for efficient insertion and deletion at any position.

• Vector is implemented as a dynamic array, allowing for efficient random access.

• Use List when the number of elements is expected to change frequently and the order of elements matters less.

• Use Vect...read more

The given string needs to be reversed and the words need to be rearranged.

• Split the string into an array of words

• Reverse the array

• Join the array elements with a space in between