Oversea company interview question.

 network, web, database, Linux system

Interview Questions

• Given a list of numbers, find a fastest sort algorithm
• Describe TCP hand shake process
• Describe DB master-slave process
• Describe the work process of a TCP proxy
• Describe the ways to defend DDOS.
• Describe what "quick sort" is, And explain its time complexity. 
• What is "index" in SQL? 
• Explain the difference between Treemap and Hashmap in Java  
• How does a website's account login system work?  
• How to reverse a doubly linked list with O(N) space complexity?
• How to sort a single string without using any api/library functions with O(N) time complexity? 

1 hour of technical test (test consists of 2 parts: MCQ (24 questions of 4-choice, correct answers could be multiple), Algorithm (write a program on paper (can be written in C/C++/C#/Java)). Topics covered in MCQ: various sorting algorithms (e.g. Heap Sort, Insertion Sort, Merge Sort, Selection Sort) (mainly on the time complexity), TCP/IP fundamentals (structure of headers / properties of connection and connectionless protocols, hand shake, closure of connection), database (shared lock/exclusive lock, SQL statement), system stability calculation, computer science (page file basic (e.g. global to system or private to individual processes, CPU scheduling (What is the minimum unit for scheduling?, Little/Big Endian Byte Order), IPC mechanism (message queue, pipeline, semaphore), programming (mainly on interpreting the memory allocation for pointers/malloc()/array/string assignment). Question for Algorithm test: Without using standard library function, write a program that covert decimal to hexadecimal, check if the hexadecimal number is the same in forward order and reverse order (e.g. 0x3C3, 0x4B4 are the same in forward order and reverse order). HR questions: Reason for leaving? What do you think is required to be a great software engineer?