2-side racer

Racer 2-20180911

• Personal Introduction
  • School Experience (course, postgraduate examination, achievement)
  • Project experience (time period, Project introduction)
  • Personal Hobbies (sports, specialties)

Note: The interviewer is very interested in personal introduction (Graduate school results introduced this piece)

• Data
  • What are the data structures familiar
    • Array
    • LinkedList
    • Stack
    • Queue
    • Tree (Binarytree)
  • The difference between a data and a linked list
    • Add, delete, get time complexity
    • Whether object objects in the array are contiguous (objects, references)
• Java Collection
  • Introduction HashMap
    • Realization of data structure hash table
    • Features of HashMap
    • HashMap expansion mechanism (loadfactor, 2^n length)
    • Red and black trees red-black tree
    • The difference between a red-black tree and a balanced binary tree?
    • Why does HashMap use a red-black tree instead of a balanced binary tree?
  • The difference between HashMap and Hashtable? (3 to 4 o'clock)
  • Concurrenthashmap
    • Principle
  • Set, list differences
  • ArrayList
    • Introduction to the expansion mechanism
• Concurrent
  • Example thread-safe scenarios
  • Synchronized
  • JDK Optimizations for locks (the concepts of the following locks describe what, how)
    • Biased lock
    • Lightweight lock
    • Heavy-weight lock
  • Additional spin lock (what, how)
• Computer network
  • OSI7 layer model
  • TCP/IP5 layer model
  • TCP/IP on each layer protocol (Protocol) introduction
    • should Differences between get and post methods in layer HTTP, Telnet, FTP, SNMP, SMTP
      • http (3-4 points) (clear, logical answer)
    • Transport Layer What is the difference between TCP, UDP
      • TCP and TDP? (3 points)
      • How does TCP ensure reliable transmission? (4-5 points)
        • Three-time handshake establish connection
        • answer mechanism
        • packet check
        • timeout re-send
        flow control, congestion control
      • Introduction to the slow-start algorithm (awkward, when asked speechless)
    • Network layer IP, ICMP
      • Introducing the subnet mask
      • 255.255.255.0 How many IP addresses are in the subnet (2^8)?
      • How many host numbers are available?
• Java Fundamentals
  • final keyword usage
    • decorating classes, methods, properties
  • finally keyword usage
    • try, catch, finally usage
    • code question (presumably affecting the value of the last return variable by modifying the value of the variable separately in try, catch, finally)
  • difference between integer and int
    • buffer pool range ( -128~127)
  • differences between exception and error
    • compile-time exceptions
    • run-time exceptions
  • Memory Overflow
    • loading a large number of JAR packages
    • program dead loop
    • Creating a large number of objects
  • Stack Overflow stackoverflowerror
  • memory leaks
    • already used objects, not being released in time
    • long life-cycle objects holding short lifecycle Objects
      - framework
  spring Framework
  • Control invert IOC
    • control what
    • how to invert
  • Spring Annotations Read
    • Public @interface
    • The principle of annotations (reflection)
• MySQL Database
  • Table Connection
    • Left JOIN (3 tables and then results) matches the range of the table (minimum to maximum)
    • 123
• Algorithm hand tearing problem
  • 1. Back text character channeling
    • A. Using the stack
    • B. Double pointer to the left and right to traverse the interchange character
  • 2. Determine whether a string can be changed to a palindrome by deleting one character at most
    • A. Recursive implementation
    • B. Loop implementation
• Other
  • What else is there to ask?
    • Which department is responsible for the racer?

2-side racer