Project Euler problems (numbering) : follow naming convention.

Project-Euler/Problem009.js

@@ -0,0 +1,25 @@
+/*
+Special Pythagorean triplet
+
+A Pythagorean triplet is a set of three natural numbers, a < b < c, for which,
+
+a^2 + b^2 = c^2
+For example, 32 + 42 = 9 + 16 = 25 = 52.
+
+There exists exactly one Pythagorean triplet for which a + b + c = 1000.
+Find the product abc.
+*/
+
+const isPythagoreanTriplet = (a, b, c) => Math.pow(a, 2) + Math.pow(b, 2) === Math.pow(c, 2)
+
+export const findSpecialPythagoreanTriplet = () => {
+  for (let a = 0; a < 1000; a++) {
+    for (let b = a + 1; b < 1000; b++) {
+      for (let c = b + 1; c < 1000; c++) {
+        if (isPythagoreanTriplet(a, b, c) && a + b + c === 1000) {
+          return a * b * c
+        }
+      }
+    }
+  }
+}