1. There is a 10th-order symmetric matrix A[10][10], which adopts compressed storage method and stores its lower left triangle in row order as the main order, a[0][0] is the first element, and its first element The storage address is 800, and each element occupies 4 address spaces, so the address of a[7][6] is ()
A.936
B.932
C.928
D.924
2. In a multi-threaded single-producer single-consumer model, due to the long time for a single data producer to write to the queue and a long time for consumers to read from the queue, the blocking queue accumulates. The solution to this problem is not Which of the following is included ()
A. Use a lock-free queue instead of a locked blocking queue
B. Increase the number of consumption attempts per unit time
C. Increase the speed of consumers reading data
D. Reduce the number of generations per unit time
3. In the sql server command, the following operations can be used to delete database files are ()
A.delete
B.drop
C.remove
D.truncate
4. Any one binary tree T, if the number of nodes of degree 1, 2, 0 degree is the number of nodes is 11, which is the number of branches ()
A.24
B.23
C.22
D.21
5. If the probability of getting a taxi per unit time is the same, and the probability of getting a taxi between 19:00 and 23:00 that day is 86%, I would like to ask the little monkey to start a taxi at 20:00 and be able to get a taxi before 22:00 The probability of hitting a car is ()
A.60%
B.54%
C.49%
D.34%
6. The network interconnection equipment that cannot isolate the conflict domain is ()
A. Router
B. Switch
C. Bridge
D. Hub
7. The startup process of a home computer includes the following steps:
1. Load the master boot record
2. Disk self-check
3. Load the operating system kernel
4. Boot manager
A.2413
B.2143
C.2314
D.1234
8. In the following program segment, the number of executions of the last statement is ()
s=0;
for(i=1;i<=m;i++)
for(j=0;j<=i;j++)
s+=j ;
A.(m+3)(m+1)/2
Bm(m+3)/2
Cm(m+2)/2
Dm(m+1)/2
9. A directed graph with n vertices and e edges has () zero elements in the adjacency matrix storage structure
A. n 2 − en^2-en2−e
B. n 2 − 2 e n^2-2e n2−2e
C. 2 e 2e 2e
D. e e e
10 Xiao Yuan has opened a series of summer courses. In the following three tables, which SQL statement can be used to find out the number of students who have signed up for courses under the age of 12?
Course (course id, teacher id, subject id, class time)
students (student id, name, age, city)
registration (student id, course id, registration time)
A.select sum(distinct student id) from where students sign up id in (select student id from registration where age <=12)
B.select sum(distinct student id) from registration where student id in (select student id from student where age <=12)
C.select count(distinct student id) from registration where student id in (select student id from registration where age <=12)
D.select count(distinct student id) from registration where student id in (select student id from student where age <=12)
11. Which of the following operations is not performed during disk advanced formatting:
A. Set empty file system
B. Set root directory
C. Set disk partition
D. Set boot block
12. The running result of the following C program on a 64-bit computer is:
#include<stdio.h>
int fun1(int i);
int fun2(int i);
int fun3(int i);
int fun1(int i){ return i<2? i :fun1(i-1)-fun2(i-1); } int fun2(int i){ return i<2? i+1: fun2(i-1)-fun2(i-1 ); } int fun3(int i){ return fun1(i)/fun2(i) +2020; } int main(){ printf("%d\n",fun3(60)%4); return 0; } A.3 B.2 C.1 D.0
13. The introduction of a certain manufacturer’s video live broadcast system has the following expressions. Among them, it is impossible to achieve ()
A. Custom sound quality, single and dual channels during a call, 32kHz and 48kHz sampling rate can be freely switched
B. Real visual experience, For the original 360p video, you can also enjoy the high-definition picture quality
. C. The ultimate anti-weak network experience. Even if the packet loss rate is as high as 90%, the call can still be smooth
. Real-time interaction in milliseconds, no matter which city the other party is in the world, The call delay does not exceed 10ms
14. In the latest HTTP standard, a new transport layer protocol is used to replace the TCP transport protocol. Compared with TCP, one of the changes is the use of a 64-bit ConnectionID instead of the server address, server port, and client address , The four-element combination of the client port to identify a connection. Which of the following advantages of the new agreement is related to this change?
A. Supports custom congestion control
B. Quickly restarts the dialog when the network is switched
C. Multiplexing without head-to-head blocking
D. Low-latency connection establishment
15. Suppose that in the n system, 263*980=204500, the value of n is ()
A.14
B.13
C.12
D.11