ZeroFOX Senior Piping Engineer Interview Questions and Answers

To check if a number is a power of 2, we can use bitwise operations.

• A power of 2 has only one bit set to 1, so we can use the bitwise AND operator to check if the number is a power of 2.

• If n is a power of 2, then n & (n-1) will be 0.

• For example, 8 (1000 in binary) is a power of 2, and 8 & 7 (0111 in binary) is 0.

Sort a stack without using another data structure

• Use recursion to pop the top element and insert it at the bottom of the remaining stack

• Repeat until the stack is sorted in ascending order

• Time complexity: O(n^2), space complexity: O(n) due to recursion

Check if array has continuous increasing and decreasing values

• Loop through the array and check if each element is greater than the previous one

• Once you find the maximum element, check if the remaining elements are in decreasing order

• If yes, return true else false

Design a cricinfo (LLD)

• Identify the entities: players, teams, matches, scorecards, tournaments, etc.

• Define the relationships between entities

• Create a database schema to store the data

• Implement APIs to fetch and update data

• Design a UI to display the information

• Consider scalability and performance

• Ensure data security and privacy

The question asks to find the memory of a given structure by considering struct padding.

• Struct padding refers to the unused bytes added to align the members of a structure.

• To find the memory of a structure, we need to consider the size of each member and the padding added.

• The total memory of a structure is the sum of the sizes of its members and the padding.

Code to find the position of a number in a BST

• Implement a recursive function to traverse the BST

• Compare the target number with the current node value

• If the target is smaller, go to the left subtree; if larger, go to the right subtree

• Repeat until the target is found or the subtree is null

A Trie is a tree-like data structure used for efficient retrieval of strings. It supports insertion and search operations.

• A Trie is also known as a prefix tree.

• Each node in the Trie represents a character.

• The root node represents an empty string.

• Each node can have multiple children, each representing a different character.

• Insertion involves traversing the Trie and creating new nodes as needed.

• Search involves traversing...read more

Check if a string containing parenthesis, curly brackets, and square brackets is valid.

• Use a stack to keep track of opening brackets

• Pop from stack when encountering a closing bracket, ensuring it matches the corresponding opening bracket

• Return false if stack is not empty at the end