Baidu Data Mining engineer intern written test questions

Written questions:
First, Jane answer 30 points
1. The extern "C" {} has a good effect on the application scenario;
2. Write the two familiar design patterns, and the application scenario, you can give the pseudo-code;
3.TCP Time_wait is the state, and the application scenario, as well as the advantages and disadvantages;

Second, the algorithm problem 40 points
1. There is a task execution machine, the number of tasks n<1000, the machine can only perform one task at a time, and there is a dependency between the tasks,
However, there is no cyclic dependency between the tasks, please give the appropriate order of task execution. Algorithms, pseudo-code, and analyze their time complexity and
Complexity of space.

2. Write a function that counts the number of complete sentences in an English text, containing only uppercase and lowercase letters, spaces, dots (.), commas (,).
The complete sentence must contain at least one letter and end with a dot number.
Requirements: Complete code, achieve the goal, efficient, concise;

Iii. System Architecture 30 points
There is a monitoring system, there are a large number of data records including {URL, user access IP, time}, to maintain the monitoring system, and provide queries.
Design a can store and maintain 100 billion records, real-time monitoring, and support two kinds of queries:
1. Specify any time period (accurate to minutes) and a URL to investigate the total number of accesses for all URLs within this time period.
2. Specify any time period (accurate to minutes) and an IP to query the total number of IP accesses during this time period.

interview a
1. Introduce yourself and introduce yourself in a simple way with your resume.
2. Introduction of the project, combined with their own major projects, as well as the introduction of the project information, interactive interpretation; The interviewer's relationship is machine learning related issues.
3. Algorithm problem; binary tree non-recursive implementation of the pre-sequence traversal;
4. Algorithm design problem; How to remove duplicate pages;

interview two
1. Self-introduction; (IBID.)
2. Introduction of the project; (IBID.)
3. Algorithm problem; (slightly) asked a ttest;
4. Algorithm design questions, how to classify the query;

interview three
1. Self-introduction;
2. Introduction of the project;
3. two algorithm problems;
1> a string of beads (m), having n colors (n "=10), designing an algorithm that takes out one of the two colors in the N and minimizes the length. and analyze the complexity of time and space.
2> from 1 to 100 million, all appearing numbers and (125=1+2+5), manual computers come out;

How I feel:
1. Is the internship recruitment, and no preparation, the written test can pass has been very unexpected;
2. The ability to solve their own algorithmic problems to be improved, interview when the problem encountered in fact are very common, estimated on the Internet to see more can be answered very well;
3. Baidu written test + three-side process, roughly and online speaking almost, the first two interviews are similar, three sides may be complementary, and often ask some of your career planning problems;