Baidu Shenzhen written examination Summary

I reported to R & D engineers. I wrote the questions based on my impressions and shared them with you. It should not be a leak.

Question 1: Short answer

1. Explain the database operation steps in a short language.

Baidu Library's answer:

1. Establish a database connection
2. Open the database connection
3. Create database commands
4. Run database commands
5. Save database commands
5. Close database connection

 I only wrote three steps: open, execute, close

2. TCP/IP layer-4 protocol.

Answer on the Internet: application layer, transmission layer, Network Interconnection layer, and host to Network Layer

I wrote: data link layer, transmission layer, network layer, and Application Layer

3. Description of MVC Structure

Online answer: MVC is a design pattern that enforces ApplicationProgramSeparate input, processing, and output. MVC applications are divided into three core components: model, view, and controller. They process their own tasks.

I answered the question.

Question 2:AlgorithmAnd Programming

1. About the full arrangement. Use ~ Z and 0 ~ 9.

2. Reverse the string

3. For string matching, three known operations are provided:

Insert characters to any position;

Delete characters. Delete characters at any position;

Replacement character.

For example, a = abond; B = Abdon; calculates the minimum number of times from A to B. Here, in two steps, replace o with D and delete the last D. It is implemented recursively.

Note: 3 I did not do it. It's so sad. before the test, I saw such a similar question in "Programmer Interview Guide ".CodeIt was a little long. I didn't take a closer look at it at the time, but today I did not do anything about the tragedy.

Question 3: Design Questions

The implementation of RSA secretid is a random generation of passwords. Every 60 s generates a new password. If you have used the U shield of the Bank of China, you will know it. The question is how to design the system. The design requirements are related to the randomness of passwords and the number of tens of millions of users in the system. The last question is about algorithm updates (how to minimize modifications to servers and devices during algorithm upgrade, it uses the word "smooth ).

 

Let's talk about this. We can discuss what we can see.