Add Algorithms to Math with tests (#429)

* chore: add area and area test

* chore: add armstrong number

* chore: add factors

* chore: add perfect cube

* chore: add perfect square

* chore: add perfect number

* chore: add number of digits

* chore: fix according to standardjs

* chore: remove conflicting files

Maths/ArmstrongNumber.js

@@ -0,0 +1,24 @@
+/**
+ * Author: dephraiim
+ * License: GPL-3.0 or later
+ *
+ * An Armstrong number is equal to the sum of the cubes of its digits.
+ * For example, 370 is an Armstrong number because 3*3*3 + 7*7*7 + 0*0*0 = 370.
+ * An Armstrong number is often called Narcissistic number.
+ *
+ */
+
+const armstrongNumber = (num) => {
+  if (num < 0 || typeof num !== 'number') return false
+
+  let newSum = 0
+
+  const numArr = num.toString().split('')
+  numArr.forEach((num) => {
+    newSum += parseInt(num) ** numArr.length
+  })
+
+  return newSum === num
+}
+
+export { armstrongNumber }