Task 3 : Number system conversion

Authors

Li Chi Kin ([e-mail])

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: $0\leq n\leq 2^{64}-1$

4. The inputted number system must be an integer.

Example

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)

$5201314 = 1\times12^{6}+8\times12^{5}+10\times12^4+10\times12^3+0\times12^2+2\times12+10$

Example - Error

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

Please enter a set of number:

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.