js_code.js

/*
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

*/

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

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

week3_tech_challenge.md

Rewrite the question in your own words:

• The problem is asking to write a function that will take in a number and will return a string of roman numerals that corresponds with the number coming in. I am to use the roman numeral key provided.

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

• The problem that is being asked seems simple enough, as far as what it is asking me to do. However, I believe the solution may be more complex. My initial thought is to write a function with a series of conditionals regarding the num coming in and it will convert parts of the num to a string, then add that string to the output of calling the function again. The will need to be a condition for when the num is coming in is empty to stop the process.

Which data structure(s) do you think you'll use? What pros/cons do you see about using it/them?

• I know my solution will need to be a recursive fucntion, since that is the learning goal for this technical challenge.

Write out your initial pseudocode: (mid-level design, this should not be real code!)

1. Define the function and set a parameter of num for my input
2. Write a series of conditionals checking if the number coming in is first >= 1000, if so return M + call the function again and with the num - 1000
3. Do this for each roman numeral character
4. Write one last condition that checks if there isn't a num coming in, and if so return the last value.

What do you think the Big O complexity of your algorithm is? (just for practice)

• Since it appears my solution doesn't involve an iterator method, just conditionals without using state, I believe my Big O complexity is 0(log n) logarithmic time?