patrickodacre · July 29, 2016 10:55 · Jul 29, 2016
diff --git a/romanNumeralConverter.js b/romanNumeralConverter.js
@@ -0,0 +1,105 @@
+/*
+ * https://www.freecodecamp.com/challenges/roman-numeral-converter
+ * */
+
+/**
+ * My original solution.
+ *
+ * @param {integer} num Number to transform.
+ * @returns {string} Roman numeral equivalent.
+ */
+function convertToRoman(num) {
+
+    /*
+     * Shamelessly, I got the idea for the reference arrays on the Github
+     * solutions wiki.
+     *
+     * This one really stumped me.
+     * */
+    var decimalArrReference      = [
+            1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1
+        ],
+        romanNumeralArrReference = [
+            'M', 'CM', 'D', 'CD', 'C', 'XC', 'L', 'XL', 'X', 'IX', 'V', 'IV', 'I'
+        ];
+
+    /*
+     * Using Array.prototype.reduce() to iterate over the reference array
+     * felt cleaner than using a for loop or a while loop to iterate over the decimalArrReference array.
+     *
+     * But just to make sure, I clocked the performance and was disappointed
+     * that my favored reduce() clocked far slower. I'm not surprised, though.
+     * */
+    var romanizedNumberArr = decimalArrReference.reduce(function (accumulator, decNum, idx) {
+
+        while (decNum <= num) {
+            accumulator.push(romanNumeralArrReference[idx]);
+            num -= decNum;
+        }
+
+        return accumulator;
+
+    }, []);
+
+    return romanizedNumberArr.join('');
+}
+
+convertToRoman(36);
+
+/**
+ * "Basic" Solution found on Github.
+ *
+ * Often the "basic" solutions tend to be the best.
+ *
+ * You can see the original solution at the provided link.
+ * Hats off to the contributors there.
+ *
+ * @link https://github.com/FreeCodeCamp/FreeCodeCamp/wiki/Algorithm-Roman-Numeral-Converter
+ * @param {integer} num Number to transform.
+ * @returns {string} Roman numeral equivalent.
+ */
+var convertToRomanTwo = function (num) {
+
+    var decimalValue = [1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1],
+        romanNumeral = ['M', 'CM', 'D', 'CD', 'C', 'XC', 'L', 'XL', 'X', 'IX', 'V', 'IV', 'I'],
+        decLength    = decimalValue.length, // store length here so we don't have to recalculate it on every loop.
+        idx          = 0;
+
+    var romanized = '';
+
+    /*
+    * Loop over every value in decimalValue array.
+    *
+    * I tend to favor while loops over for loops because
+    * they clock a bit faster.
+    * */
+    while (idx < decLength) {
+
+        /*
+        * Continue to add the corresponding
+        * romanNumeral to the converted string
+        * until the current decimalValue doesn't
+        * fit into the num any more.
+        * */
+        while (decimalValue[idx] <= num) {
+
+            /*
+            * Concat the roman numeral to the converted string.
+            * */
+            romanized += romanNumeral[idx];
+
+            /*
+            * continue to reduce the num by the decimalValue
+            * otherwise we'd get an infinite loop.
+            * */
+            num -= decimalValue[idx];
+        }
+
+        // Move onto the next value in decimalValue array.
+        idx ++;
+    }
+
+    return romanized;
+}
+
+convertToRomanTwo(36);