AlphaSense Software Developer Interview Questions and Answers

Connect adjacent nodes at the same level in a binary tree by setting next pointers.

• Traverse the tree level by level using a queue.

• For each level, connect nodes using the next pointer.

• Set the next pointer of the last node in each level to NULL.

• Use constant space aside from input constraints.

• Example: Input - 1 2 3 4 -1 5 6 -1 7 -1 -1 -1 -1 -1 -1, Output - 1 # 2 3 # 4 5 6 # 7 #

Detect and remove loop in a singly linked list efficiently.

• Use Floyd's Cycle Detection Algorithm to detect the loop in the linked list.

• Once the loop is detected, use two pointers to find the start of the loop.

• Break the loop by setting the next pointer of the last node in the loop to null.

Find the median of two sorted arrays by merging them and calculating the median of the combined array.

• Merge the two sorted arrays into one sorted array.

• Calculate the median of the merged array based on the total number of elements.

• If the total number of elements is even, take the mean of the two middle elements as the median.

Retrieve leaf nodes from a binary tree in left to right order, prioritizing lesser depth or smaller node data if equidistant from leftmost node.

• Traverse the binary tree in level order and keep track of leaf nodes.

• Prioritize leaf nodes with lesser depth or smaller node data if equidistant from leftmost node.

• Return the list of leaf nodes in the order they appear from left to right.

Key concepts related to virtual memory and potential follow-up questions

• Key concepts: paging, segmentation, page tables, TLB, page faults, thrashing

• Follow-up questions: How does virtual memory differ from physical memory? What is the role of the operating system in managing virtual memory? How does virtual memory improve system performance?

• Example: Explain the concept of page tables and how they are used in virtual memory management

Create a program to print last 10 lines from a file and trigger itself every minute.

• Read the file and store the last 10 lines in a data structure like a queue or array

• Use a timer to trigger the program every minute

• Print the last 10 lines from the data structure