To prepare for his tour, Santa needs to do it with his elves.
He uses a unique identifier called EID to recognize who's who.
Design a system that can handle
EID
EID stands for "Elf Identifier" it is a unique id representing an elf composed by X characters.
Elves are magically created each year but limited to 999 birth maximum.
Here are the requirements:
| Positions | Meaning | Possible values |
|---|---|---|
| 1 | Sex : 1 for Sloubi, 2 for Gagna, 3 for Catact |
1, 2 or 3 |
| 2, 3 | Last two digits of the year of birth (which gives the year to the nearest century) | From 00 to 99 |
| 4, 5, 6 | "Serial number": birth order | From 001 to 999 |
| 7, 8 | control key = complement to 97 of the number formed by the first 6 digits of the EID modulo 97 | From 01 to 97 |
Here is an example of such id:
Use Canon TDD to implement the validation logic for Santa.
More explanations by Kent Beck here.
