ServiceNow计算机科学面经_ServiceNow计算机科学面试真题及高频题

1.Implement preOrder and postOrder Traversal for a B-Tree in Java

2.Maximize Product of Five Numbers in an Array

3.Linkedlist Middle Node and Loop Detection

4.Basic Binary Search

5.Count and Say Problem

6.Basic Knowledge Questions

7.JavaScript Design: MySet Implementation

8.Java Design: Roman To Integer Converter

9.Design a CSV File Reader and Calculator

10.Find First Missing Positive Number

11.Move Zeroes to the Right

12.Match Nuts and Bolts Optimally

13.Debugging a File Directory Implementation in JavaScript

14.Optimize the Service for High Traffic

15.Handle Distance Calculation for Multiple Users

16.Convert the Solution to Object-Oriented Design

17.Find the Closest Coffee Shops

18.Modified 2Sum Problem

19.Terminal commands to list all Java processes

20.How to check if a user form is filled out correctly

21.How to verify the validity of a Social Security Number (SSN)

22.Write test cases for different fields considering character length and type

23.Find All Pairs in an Integer Array with Sum Equal to a Target Value

24.Troubleshooting a Hanging Process

25.How would you design a deck of playing cards in a database?

26.What are the principles of Object-Oriented Programming (OOP)?

27.What is polymorphism in computer science?

28.Design a query function for an unsorted array to find the minimum value within a given range

29.Algorithm to find the minimum absolute difference between elements of two sorted arrays

30.Implement a JavaScript function to extend all arrays with a method to get the cube of their elements

31.Matrix Zeroes Problem

32.Object-Oriented Design: Elevator System

33.Design Patterns Knowledge

34.Java Versions: Differences between Java 7 and Java 8

35.Data Structures: Stack vs Queue

36.Valid Words Count in a String

37.System Design Interview

1. Implement preOrder and postOrder Traversal for a B-Tree in Java

Discuss the preOrder traversal for a B-Tree and implement it in Java. Write the Node class and print the preOrder output. Provide both recursive and iterative implementations. As a follow-up, implement the postOrder traversal using an iterative approach. Consider the possibility of duplicate values and discuss how you might handle them, for example, using a stack or a set to store nodes. Finally, explain how postOrder can be thought of as a mirrored version of preOrder, where you would change the order of pushing children and then reverse the result to achieve the postOrder output.

2. Maximize Product of Five Numbers in an Array

Given an array, find the maximum product that can be obtained from any five numbers in the array. The solution should consider the following cases: the product of the five largest positive numbers, the product of the two smallest negative numbers and the three largest positive numbers, and the product of the four smallest negative numbers and the largest positive number. You should not sort the array; instead, scan through the data once to find the five largest positive numbers and the four smallest negative numbers, then compare to find the maximum product. Write code to implement this logic.

3. Linkedlist Middle Node and Loop Detection

Write a function to find the middle node of a linked list, and another function to detect a loop in a linked list using the fast and slow pointer technique.

4. Basic Binary Search

Write the most basic form of binary search without any variations.

5. Count and Say Problem

Implement a function that transforms a string by counting the consecutive characters. For example, the input 'aaabbcdd' should be converted to 'a3b2c1d2'.