roman_numeral_recursion.md

Instructions

1. Fork this gist, then "edit" the gist
2. Fill out the questions below
3. Click the "Add file" button and add your source code to the gist
4. Submit by the due time as instructed in Zoom

Do not publish your code on a public repl.it or repo or other public means.

Prompt

Write a recursive function that converts an integer into a string such that the number is represented in Roman Numerals in the most efficient way. eg, the number 4 could be written as 'IIII' but it's more efficient to use 'IV' since that's a shorter string Assume no number is greater than 4,000 Here are the Roman Numeral equivalents you'll need to know:

• M=1000
• CM=900
• D=500
• CD=400
• C=100
• XC=90
• L=50
• XL=40
• X=10
• IX=9
• V=5
• IV=4
• I=1

Rewrite the question in your own words:

With a function that takes in an integer and return a string of that number in roman numerals

What assumptions will you make about this problem if you cannot ask any more clarifying questions? What are your reasons for making those assumptions?

I will need to do some simple math with conditional statements. If it doesn't hit one of the "milestones" for a new roman numeral character, I need that character with the symbol that represents the amount I will need to subtract.

What are your initial thoughts about this problem? (high level design, 2-3 sentences)

It seems like I will need a lot of conditionals...but maybe there is a way to condense it

How would you identify the elements of this problem?

• Searching of Data
• Sorting of Data
• Pattern Recognition
• Build/Navigate a Grid
• Math
• Language API knowledge
• Optimization

Which data structure(s) do you think you'll use? What pros/cons do you see with that choice?

Numbers and strings

Write out a few lines of initial pseudocode: (mid-level design, this should be short, and not be real code!)

check if argument is greater or less than a certain amount (check against largest first)
then do the same process with the remainder but skip first conditional
call func until number hits zero

the terminating scenario: when numbers hits zero

What do you think the Big O complexity of your algorithm is? (time complexity and space complexity)

JS Starter Code

function toRoman(num) {
  // your code goes here
}

console.log(toRoman(128));  // should return "CXXVIII"
console.log(toRoman(2000)); // should return "MM"
console.log(toRoman(2017)); // should return "MMXVII"
console.log(toRoman(1999)); // should return "MCMXCIX"

Ruby Starter Code

def to_roman(num)
  # your code goes here
end

puts to_roman(128)   # should return "CXXVIII"
puts to_roman(2000)  # should return "MM"
puts to_roman(2017)  # should return "MMXVII"
puts to_roman(1999)  # should return "MCMXCIX"