README.md

Back to Main

Task 1: Number system convertor

0xdeadbeef = 3735928559

Authors

Li Chi Kin (ckliam@connect.ust.hk)

Problem

This task is designed for fun :)

There are so many number systems. We encounter some unusual number systems in our daily lives, namely, decimal (base 10), duodecimal (base 12), and trinary (base 3).

Write a Number System Converter that converts a number from one system to another. You have to handle 3 systems: decimal, duodecimal, and trinary. The converter should be able to convert from/to any of the three systems.

Assumption

1. There are no spaces between the digits of the input string.
2. The input string is a non-negative integer. Or else it throws an error message.
3. The input and output values are in range: $0\le n\le 2^{64}-1$
4. The inputted number system must be an integer.

Example

(Do not add an extra newline for the case of succesful conversion)

This is an example that converts 123123123 from decimal to trinary:

Please enter a set of number:
123123123
Please enter the current number system:
10
Please enter the number system you want the set of number be converted to:
3
Output=22120200022011200

This is an example that converts 5201314 from decimal to duodecimal (base 12)

Please enter a set of number:
5201314
Please enter the current number system:
10
Please enter the number system you want the set of number be converted to:
12
Output=18AA02A

You can verify the answer as below:

(A = 10, B = 11)

$$5201314=1\times {12}^6+8\times {12}^5+10\times {12}^4+10\times {12}^3+0\times {12}^2+2\times 12+10$$

Example - Error

However, if the user entered a wrong number system, an error message should be printed:

Please enter a set of number:

(Error messages has newlines at the end)

Please enter a set of number:
9999 
Please enter the current number system:
3
Error! That set of number is not a trinary number.

Please enter a set of number:
ABCDEF 
Please enter the current number system:
12 
Error! That set of number is not a duodecimal number.

Please enter a set of number:
987456321
Please enter the current number system:
27
Error! The number system is not supported.

How to Run Your Code

To run the code, you need to make sure that you are first in the right folder/directory in your terminal (the text area under your code): Currently, in the example, the user is in the directory /workspaces/codespaces-blank you need to get to /workspaces/codespaces-blank/<homework-repository-name>/hw1 to run your main.c code, do this by writing the command cd <homework-repository-name>/hw1 (cd: change directory) and press enter.

(Note: if you want to go up a folder you can use cd ..)

Note that you need to do this everytime you open the Github Codespace.

Once you are in the direcctory, run the following command in the terminal:

gcc -o homework.exe main.c && ./homework.exe 

To give input, you can write in the terminal directly and press enter when you are finished.

(Note: for a C code to run, we need to make it an executable file, then run it)

Submission

Modify your main.c file. We still use Github Classroom to grade your submissions, the instruction is still similar to the one in Tutorial 0 README.md.