Technical Test - Node.js Developer
Suggested time limit: 2 hours
It is not compulsory to complete all tasks - it is better to have a working solution to task 1 than incorrect solutions to all tasks.
Submission
- Create a public github repo
- push your code to it
- tell us where to find it and what version of node you've used
Have fun ...
Part I
The numeric system represented by Roman numerals originated in ancient Rome and remained the usual way of writing numbers throughout Europe well into the Late Middle Ages. Numbers in this system are represented by combinations of letters from the Latin alphabet. Roman numerals, as used today, are based on seven symbols:
| Symbol | I | V | X | L | C | D | M |
|---|---|---|---|---|---|---|---|
| Value | 1 | 5 | 10 | 50 | 100 | 500 | 1000 |
In its simplest form, the numbers 1 to 10 are expressed as follows:
I, II, III, IIII, V, VI, VII, VIII, VIIII, X
Some examples of larger numbers include:
| Positional Arabic | Roman |
|---|---|
| 12 | XII |
| 25 | XXV |
| 140 | CXXXX |
| 1954 | MDCCCCLIIII |
| 1990 | MDCCCCLXXXX |
| 2014 | MMXIIII |
| 2017 | MMXVII |
Task 1
Using node.js, Create a javascript function toSimpleRoman that can convert from our modern numbering system (positional Arabic numerals) to Roman numerals, e.g.
> toSimpleRoman(9)
> VIIII
>
> toSimpleRoman(12)
> XII
>
> toSimpleRoman(1990)
> MDCCCCLXXXX
>
> toSimpleRoman(140)
> CXXXX
Part II
In a few specific cases, to avoid confusing and hard to read numbers with four characters repeated in succession (such as IIII or XXXX), subtractive notation is used, as in this table:
| Number | 4 | 9 | 40 | 90 | 400 | 900 |
|---|---|---|---|---|---|---|
| Notation | IV | IX | XL | XC | CD | CM |
The numbers 1 to 10 are thus more commonly expressed in Roman numerals as follows:
I, II, III, IV, V, VI, VII, VIII, IX, X.
Some examples of the modern use of Roman numerals include:
| Positional Arabic | Roman |
|---|---|
| 12 | XII |
| 25 | XXV |
| 140 | CXL |
| 1954 | MCMLIV |
| 1990 | MCMXC |
| 2014 | MMXIV |
| 2017 | MMXVII |
Task 2
Using node.js, Create a javascript function toCompactRoman that converts from our modern numbering system to Roman numerals, using the more compact subtractive notation as described earlier in this section, e.g.:
> toCompactRoman(9)
> IX
>
> toCompactRoman(12)
> XII
>
> toCompactRoman(1990)
> MCMXC
>
> toCompactRoman(140)
> CXL
Task 3
Using node.js, create a javascript function toArabic that converts from roman numerals to our modern (positional arabic) numbering system, e.g.
> toArabic('XII')
> 12
>
> toArabic('MCMXC')
> 1990