Create roman_to_integer.js

Author: TheCoderSingh

roman_to_integer.js

@@ -0,0 +1,47 @@
+/**
+ * @param {string} s
+ * @return {number}
+ */
+var romanToInt = function(s) {
+    let sum = 0;
+
+    let i = 0;
+
+    while(i < s.length) {
+        switch(s[i]) {
+            case "I":
+                if(s[i + 1] === "V" || (s[i + 1] === "X"))
+                    sum -= 1;
+                else
+                    sum += 1;
+                break;
+            case "V":
+                sum += 5;
+                break;
+            case "X":
+                if(s[i + 1] === "L" || s[i + 1] === "C")
+                    sum -= 10;
+                else
+                    sum += 10;
+                break;
+            case "L":
+                sum += 50;
+                break;
+            case "C":
+                if(s[i + 1] === "D" || s[i + 1] === "M")
+                    sum -= 100;
+                else
+                    sum += 100;
+                break;
+            case "D":
+                sum += 500;
+                break;
+            case "M":
+                sum += 1000;
+                break;
+        }
+        i++;
+    }
+
+    return sum;
+};