Online pen questions of a senior enterprise

Labels: OS using Java data SP time C Ad Algorithm

Collected online pen questions from Alibaba this year and posted them for your reference.

1. Which of the following functions is a system call rather than a library function ______?
Printf
Scanf
Fgetc
Read
Print_s
Scan_s

2. A football team has four foreign aids from Brazil, the Netherlands, Italy, and the United States. They are good at forward, guard, and guard respectively, including:
① U.S. foreign aid is dedicated to defending the door;
② Italian foreign aid is not good at forward;
③ Brazilian foreign aid is at the same position as another foreign aid;
④ Dutch foreign aid is good at different places than Brazilian foreign aid.
Which of the following conditions can be used to offer Brazilian foreign aid ______.
Forward
Shoumen
Defender
Forward or guard
Defender or defender
Forward or defender

3. Use a truck to transport n hard disks with 1 TB of data, and deliver the data to the destination at 1000km km/h; at least ______ hard disks can be transported by trucks to make the transmission rate exceed 1000 Gbps.
2000
3000
4000
5000
6000
7000

4. What is the difference between the wait () method and sleep () method in Java?

5. A Query and a text are all composed of lowercase letters. It is required to find the length of the longest consecutive letter sequence that appears continuously in the query in the same order in text. For example, if the query is "acbac" and the text is "acaccbabb", the "CBA" in the text is the longest sequential letter sequence that appears in the query. Therefore, the returned result must be 3 characters long. Pay attention to program efficiency.

6. Write a function and input a binary tree. each node in the tree stores an integer. The function returns the absolute value of the difference between the two nodes with the greatest difference in the binary tree. Pay attention to program efficiency.

7. If a museum visitor arrives at a rate of 20 people per minute, and each person stays in the museum for 20 minutes on average, which of the following rows of talent is required for the museum?
100 people
200 people
300 people
400 people
500 people
600 people

8. A turkey was born in spring. From the first day of birth, the master will feed it every day. This turkey uses a model to calculate the degree of the master's love for it = the number of days of rice/(the total number of days after birth + 1 ). This Turkey finds that the love index is rising every day. One day, Thanksgiving day arrived, and the turkey was killed by its host. Which of the following statements about Turkey's love index model is true :______?
The reason why the turkey model is invalid is that this formula is not the maximum likelihood estimation.
The reason why the turkey model is ineffective is that the love index grows fast first and then slowly.
The reason why the turkey model is ineffective is that the variance of the love index is not calculated.
The reason why the turkey model is invalid is that the denominator is + 1.
The reason why the turkey model is ineffective is that the master is too bad.
The reason why the turkey model is invalid is that the statistical probability space is incomplete.

9. Which of the following statements is wrong ______.
Five options are correct in this question.
B is correct
D. Correct
Def is correct
There is an error in ABC
If both ABCDE are correct, then f is also correct.

10. For the 100 students in the class, the teacher asked them to play the following game: each student writes an integer between 1 and 100 (including 1 and 100) on the paper and cannot refer to the numbers written by others, whoever has the number closest to 3/4 of all the numbers will get 100 yuan. Which of the following is the worst choice :______?

11. The relative speed of concurrent process execution is ______.
Determined by the program structure of the process
Controlled by the process itself
Determined when a process is created
Related to the Process Scheduling Policy
Depends on the process destruction time
Determined by the Memory Allocation Policy

12. The "Village Chief" took 4 pairs of fathers and sons to the shooting of a village in the third quarter of "Where is Dad. There is a millennial rule in the village to protect children from being abducted, that is, when they eat, they can only be other children or their own parents. Which of the Four Parent and Child members can sit on the Round Table. (If you rotate it, it is a new way to sit in the face of changing directions)

13. There is a bottle containing salt with a volume of W. After the salt is used up, some salt powder (volume can be ignored) remains on the bottle wall. Now I want to modify the sugar in the bottle and give you u-volume purified water to clean the bottle. After each cleaning, the bottle contains at least V of water (salt solution, which can ignore the volume of salt ). Suppose W> U> V, which of the following methods can be used to clean the bottle ______?

Pour all the purified water into the bottle and then drop the water.
The purified water is divided into two equal parts, and the bottle is washed with each part of water.
Clean the bottle with purified water injected with V each time until the purified water is used up.
Clean the bottle with 2 V purified water injected each time until the purified water is used up.
Inject the used water into the bottle again and clean it multiple times.
The above methods have the same cleansing effect.

14. The random number generated by the algorithm is "pseudo-random". That is to say, after the first number is set, the sequence of the subsequent numbers is determined, in addition, after a very large loop, the system will return to the first number and then start again and again. Obviously, the lottery and lottery programs cannot be implemented through pseudo-random numbers. In reality, real random numbers are often implemented based on a certain thermal noise. If a hot noise is a standard normal distribution, can it be converted to a uniform distribution in the (0, 1) interval ______?

The measurement and calculation errors are ignored and can be converted to an even distribution in the (0, 1) range.
It cannot be converted to an even distribution in the (0, 1) interval.
Unable to judge due to insufficient information.
The pseudo-random number generation algorithm can be used to convert the data to an even distribution in the (0, 1) interval.
A pseudo-random number generation algorithm can generate an even distribution in the (0, 1) interval.
None of the above statements are correct.

15. In the following options, ______ is the sequence of states that a typical tcp client experiences (actively establishing a connection and actively disconnecting.
Sync_sent-> established-> fin_wait_1-> fin_wait_2-> time_wait
Sync_sent-> established-> fin_wait_1-> fin_wait_2-> close_wait
Sync_sent-> sync_rcvd-> established-> fin_wait_1-> fin_wait_2
Sync_rcvd-> established-> close_wait-> time_wait-> last_ack
Sync_rcvd-> established-> close_wait-> time_wait-> fin_wait1
Sync_send-> established-> fin_wait1-> time_wait-> close_wait

16. Each physical computer can Virtualize 20 virtual machines. Assume that a virtual machine fails only when the physical machine it hosts fails. Five physical machines Virtualize 100 virtual machines. Which of the following statements about the failure of these 100 virtual machines are true :______?
The failure rate of a single virtual machine is higher than that of a single physical machine.
The failure of the 100 virtual machines is independent of each other.
The number of failures of the 100 virtual machines per unit time is higher than the number of failures of the 100 physical machines per unit time.
It is impossible to determine which of the 100 virtual machines and 100 physical machines are more reliable.
If five virtual machines are randomly selected to form a cluster, the reliability of the cluster is the same as that of the five physical machines.
Only one virtual machine may fail for a while.

17. Several channels waiting for access to the disk in turn are, and 76. The current head is located in the cylindrical cylinder 40. If the shortest time is used to prioritize the disk scheduling algorithm, the access sequence is ______.
19,43, 40,4, 79,11, 76
, 79
, 4
, 19
, 19
40, 19, 11, 4, 79,76, 43

18. The opposite parties compete for an item with a value of 1. The two sides can adopt a strategy that can be divided into a pigeon strategy and an e strategy. If both parties adopt a pigeon strategy, each party has a 1/2 chance of obtaining the item. If both parties adopt an e strategy, each party has a 1/2 probability of winning. The winner has a value of 1, if one party pays a price of 1 and the negative party pays a price of 1, if one party uses a pigeon strategy and the other party uses an e strategy, then the e strategy obtains an item with a value of 1. No one knows whether the opponent is a pigeon strategy or an e strategy before the competition results. When the proportion of the person who chooses the pigeon strategy is a certain value, the expected benefits of the pigeon strategy and the e strategy are the same. The value is:
0.2
0.4
0.5
0.7
0.8
None of the above

19. A legal expression is surrounded by (), and () can be nested and connected. For example, () is also a legal expression. Currently there are 6 pairs (), which of the following are the valid expressions ______.
15
30
64
132
256
360

Online pen questions of a senior enterprise