This time, a slight revision was made, and the algorithm and the English document were split. The specific content has been output in the previous two days'articles, so a summary of these two parts is made in this article.

Of course, the technical aspects are output here first, then consider the rectification.Step by step, and break up the content, so as not to accumulate a lot of knowledge points in an article, making it difficult for everyone to digest, my previous way should be wrong.

Persistence is a virtue, change is a way, Come on!

Algorithm LeetCode algorithm

Leetcode algorithm [34 looks for elements in a sorted array]

Last time we learned how to find the dichotomy, we tried to find a problem with moderate difficulty in the dichotomy.

But the dichotomy is just one solution. If you don't have any idea at first, we'll have to find the target number in a clumsy linear search.Complete first, then perfect, is also a way of learning.

Slowly, keep going, and you will feel that practice makes life, you think.

Review Reads and Comments on at least one English Article

What is the use of Java Abstract classes?

Yesterday, I did a lame translation of the English documents, but this is a very simple article about abstract Java classes, which is easy to understand and suitable for getting started.

Looking at the documents, I also read a lot of articles and found that foreign friends and what we pursue are the same, starting from the most basic aspects, and the examples are simple, so that beginners can see at a glance.

For deep-level articles, Xiao Edition had only made a rough look before, and only made some impressions.The next step is to add an article translation, read through the full text, just like reading our own articles, to make a postview, the effect should be fried chicken sticks, but also to improve English reading ability by the way.

Tip A Technical Skill

1. service

The service command is used to run System V init scripts, which are usually located under the / etc/init.d file. This command can run scripts directly inside this folder without adding a path

View service status
$ service ssh status

View all service status
$ service --status-all

Restart Service
$ service ssh restart

1. ps

The ps command displays information about the running process. There are many options for the ps command, and only a few are listed here.

View all currently running processes
$ ps -ef | more

Show currently running processes in a tree structure, and the H option shows the hierarchy of processes
$ ps -efH | more

1. free

This command displays the current memory usage of the system, including used, available, and swapped memory

//free outputs memory usage in bytes by default

$ free
total       used       free     shared    buffers     cached
Mem:       3566408    1580220    1986188          0     203988     902960
-/+ buffers/cache:     473272    3093136
Swap:      4000176          0    4000176
//If you want to output memory usage in other units, you need to add an option, -g for GB, -m for MB, -k for KB, and-b for bytes.

$ free -g
total       used       free     shared    buffers     cached
Mem:             3          1          1          0          0          0
-/+ buffers/cache:          0          2
Swap:            3          0          3

//If you want to see a summary of all memory, use the -t option, which adds a summary line to the output

ramesh@ramesh-laptop:~$ free -t
total       used       free     shared    buffers     cached
Mem:       3566408    1592148    1974260          0     204260     912556
-/+ buffers/cache:     475332    3091076
Swap:      4000176          0    4000176
Total:     7566584    1592148    5974436

1. top

top The command displays some of the most resource-intensive processes in the current system (default is CPU Occupancy Sorting) If you want to change the sort order, you can click in the results list O(Capital O)All columns that can be used for sorting are displayed, at which point you can select the columns you want to sort

Current Sort Field:  P  for window 1:Def
Select sort field via field letter, type any other key to return

a: PID        = Process Id              v: nDRT       = Dirty Pages count
d: UID        = User Id                 y: WCHAN      = Sleeping in Function
e: USER       = User Name               z: Flags      = Task Flags
........
//You can use the -u option if you only want to show processes for a specific user

$ top -u oracle

1. df

Displays the disk usage of the file system, by default df -k Output disk usage in bytes

$ df -k
Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/sda1             29530400   3233104  24797232  12% /
/dev/sda2            120367992  50171596  64082060  44% /home
//Use the -h option to display disk usage in a more readable way

$ df -h
Filesystem                  Size   Used  Avail Capacity  iused      ifree %iused  Mounted on
/dev/disk0s2               232Gi   84Gi  148Gi    37% 21998562   38864868   36%   /
devfs                      187Ki  187Ki    0Bi   100%      648          0  100%   /dev
map -hosts                   0Bi    0Bi    0Bi   100%        0          0  100%   /net
map auto_home                0Bi    0Bi    0Bi   100%        0          0  100%   /home
/dev/disk0s4               466Gi   45Gi  421Gi    10%   112774  440997174    0%   /Volumes/BOOTCAMP
//app@izenesoft.cn/public  2.7Ti  1.3Ti  1.4Ti    48%        0 18446744073709551615    0%   /Volumes/public
//Show file system type with -T option

$ df -T
Filesystem    Type   1K-blocks      Used Available Use% Mounted on
/dev/sda1     ext4    29530400   3233120  24797216  12% /
/dev/sda2     ext4   120367992  50171596  64082060  44% /home

Share is a technical article with opinions and thoughts

Design mode to get up.

Public address:
State mode of design mode (1)

"Run Bar Attack City Lion" Thank you for your attention