HKDSE ICT Question Review (20241017) / hkGalden 香港郊登

#1 綜援養懶人

17/10/24 05:00

1. In a PC with Windows 11 installed, if the desktop is idle for more than 5 minutes, the lock screen will appear. Suggest a method to bypass the lock screen.

#2 綜援養懶人

17/10/24 05:02

Solution:

Write a powershell script that repeated emulation of pressing a keyboard button happens within the interval of no more than 299 seconds.

#3 綜援養懶人

17/10/24 05:11

2. Given an Win11 account name you are using TORTOISE, suggest a method to obtain the password expiry date and export it.

Solution:

Press Win + R to launch run window, then type cmd and press enter to launch command prompt. Next, type the following command and press enter:

net user TORTOISE > C:\users\TORTOISE\desktop\password.txt

Then the result will be exported to a plain text file on your desktop.

#4 綜援養懶人

17/10/24 05:12

2. Given an Win11 account name you are using TORTOISE, suggest a method to obtain the password expiry date and export it.

Solution:

Press Win + R to launch run window, then type cmd and press enter to launch command prompt. Next, type the following command and press enter:

net user TORTOISE > C:\users\TORTOISE\desktop\password.txt

Then the result will be exported to a plain text file on your desktop.

You will see something like this from the password.txt file:

#5 綜援養懶人

17/10/24 05:17

A small trick from Question 2:

You can type the following command to shorten the result by using find command at the same time:

C:\>net user TORTOISE| find "Password expires"

Password expires 21.04.12 13:44

#6 綜援養懶人

17/10/24 05:22

3. A program Wechat.exe is running on your Win11 background. Suppose it has no administrator privileges, suggest a method to kill the process without using Task Monitor.

Solution:

In command prompt or when creating a shortcut, type the following command:

taskkill /f /im Wechat.exe

Note that if you wanna kill Windows Defender Anti-virus Service, you will get "Access is Denied" alert even if you log on as administrator. Yes, Win10 onwards is a bloatware having complete control of your PC.

#7 綜援養懶人

17/10/24 05:23

3. A program Wechat.exe is running on your Win11 background. Suppose it has no administrator privileges, suggest a method to kill the process without using Task Monitor.

Solution:

In command prompt or when creating a shortcut, type the following command:

taskkill /f /im Wechat.exe

Note that if you wanna kill Windows Defender Anti-virus Service, you will get "Access is Denied" alert even if you log on as administrator. Yes, Win10 onwards is a bloatware having complete control of your PC.

Task Manager

#8 綜援養懶人

17/10/24 05:30

4. How to read an PDF file without Adobe Acrobat DC installed?

Solution:

Office 365 app

OR

Samsung Notes app

OR from PC

Libreoffice Draw

OR from Desktop

Microsoft Edge

OR

Google Chrome

OR

Mozilla Firefox

OR

Foxit Reader

OR

PDFill PDF Editor Profesional

#9 綜援養懶人

17/10/24 06:00

5. There are 2 jpeg photos of following colors:

Pic 1: Greyscale

Pic 2: 24-bit RGB

Explain why Pic 2 has a smaller file size.

Solution:

All bits are used for Greyscale, but 24-bit RGB is not. 24-bit = 2^24 bits while Greyscale uses 256 bits = 2^8 bits. By running heap sort as a compression algorithm, Pic 2 will show better efficiency and thus lower Big-O notations.

#10 熱水味孤打

18/10/24 04:26

5. There are 2 jpeg photos of following colors:

Pic 1: Greyscale

Pic 2: 24-bit RGB

Explain why Pic 2 has a smaller file size.

Solution:

All bits are used for Greyscale, but 24-bit RGB is not. 24-bit = 2^24 bits while Greyscale uses 256 bits = 2^8 bits. By running heap sort as a compression algorithm, Pic 2 will show better efficiency and thus lower Big-O notations.

應該答錯

#11 昇撚集團

18/10/24 05:34

5. There are 2 jpeg photos of following colors:

Pic 1: Greyscale

Pic 2: 24-bit RGB

Explain why Pic 2 has a smaller file size.

Solution:

All bits are used for Greyscale, but 24-bit RGB is not. 24-bit = 2^24 bits while Greyscale uses 256 bits = 2^8 bits. By running heap sort as a compression algorithm, Pic 2 will show better efficiency and thus lower Big-O notations.

應該答錯

烏蛇係無錯架錯既係呢個世界

#12 熱水味孤打

18/10/24 06:07

5. There are 2 jpeg photos of following colors:

Pic 1: Greyscale

Pic 2: 24-bit RGB

Explain why Pic 2 has a smaller file size.

Solution:

All bits are used for Greyscale, but 24-bit RGB is not. 24-bit = 2^24 bits while Greyscale uses 256 bits = 2^8 bits. By running heap sort as a compression algorithm, Pic 2 will show better efficiency and thus lower Big-O notations.

應該答錯

烏蛇係無錯架錯既係呢個世界

問題應該係想問，明明rgb係 more information per pixel than grey scale，但點解rgb個幅file size 會細過Grey scale個幅圖

答案應該好簡單無咁複雜

就係Grey scale個幅圖dimension 大過rgb個幅圖, 一係就係rbg個幅圖好簡單無乜information, eg成幅圖紅色，咁好簡單唔洗認每粒咩色，部機記住repeat 紅色就得 (not how jpeg comrpession works, but you get the idea)

大家都用jpeg, compression efficency 係完全唔關事

之我所知，big O係講run time time complexity /memory complexity，係佢講嘅所謂compression 到姐係你run compression個時用左幾多memory/ time，同最後嘅file size係無完全關係，所以係無需要拎big O 出嚟

#13 綜援養懶人

18/10/24 22:58

應該答錯

烏蛇係無錯架錯既係呢個世界

問題應該係想問，明明rgb係 more information per pixel than grey scale，但點解rgb個幅file size 會細過Grey scale個幅圖

答案應該好簡單無咁複雜

就係Grey scale個幅圖dimension 大過rgb個幅圖, 一係就係rbg個幅圖好簡單無乜information, eg成幅圖紅色，咁好簡單唔洗認每粒咩色，部機記住repeat 紅色就得 (not how jpeg comrpession works, but you get the idea)

大家都用jpeg, compression efficency 係完全唔關事

之我所知，big O係講run time time complexity /memory complexity，係佢講嘅所謂compression 到姐係你run compression個時用左幾多memory/ time，同最後嘅file size係無完全關係，所以係無需要拎big O 出嚟

望真啲

Greyscale saving as RGB = poorer compression

#14 綜援養懶人

18/10/24 22:59

一般而言，相片 by default 係 save as RGB

題目暗示咗 same dimension (resolution)

#15 熱水味孤打

19/10/24 01:46

烏蛇係無錯架錯既係呢個世界

問題應該係想問，明明rgb係 more information per pixel than grey scale，但點解rgb個幅file size 會細過Grey scale個幅圖

答案應該好簡單無咁複雜

就係Grey scale個幅圖dimension 大過rgb個幅圖, 一係就係rbg個幅圖好簡單無乜information, eg成幅圖紅色，咁好簡單唔洗認每粒咩色，部機記住repeat 紅色就得 (not how jpeg comrpession works, but you get the idea)

大家都用jpeg, compression efficency 係完全唔關事

之我所知，big O係講run time time complexity /memory complexity，係佢講嘅所謂compression 到姐係你run compression個時用左幾多memory/ time，同最後嘅file size係無完全關係，所以係無需要拎big O 出嚟

望真啲

Greyscale saving as RGB = poorer compression

不如你再望真d睇下你自己send條link出嚟下面d discussion

#16 綜援養懶人

19/10/24 01:57

問題應該係想問，明明rgb係 more information per pixel than grey scale，但點解rgb個幅file size 會細過Grey scale個幅圖

答案應該好簡單無咁複雜

就係Grey scale個幅圖dimension 大過rgb個幅圖, 一係就係rbg個幅圖好簡單無乜information, eg成幅圖紅色，咁好簡單唔洗認每粒咩色，部機記住repeat 紅色就得 (not how jpeg comrpession works, but you get the idea)

大家都用jpeg, compression efficency 係完全唔關事

之我所知，big O係講run time time complexity /memory complexity，係佢講嘅所謂compression 到姐係你run compression個時用左幾多memory/ time，同最後嘅file size係無完全關係，所以係無需要拎big O 出嚟

望真啲

Greyscale saving as RGB = poorer compression

不如你再望真d睇下你自己send條link出嚟下面d discussion

你想 Greyscale saves as Greyscale (jpg/png)，

得，Xnview可以慢慢set，其他軟件未必支援