chore: count set bits using bitwise ops (TheAlgorithms#1532)

* Update BinaryCountSetBits.js

* Use `let` instead of `var`

---------

Co-authored-by: Lars Müller <34514239+appgurueu@users.noreply.github.com>

Author: imrahulkb

Bit-Manipulation/BinaryCountSetBits.js

@@ -14,8 +14,13 @@ function BinaryCountSetBits(a) {
 
   if (!Number.isInteger(a)) throw new TypeError('Argument not an Integer')
 
-  // convert number into binary representation and return number of set bits in binary representation
-  return a.toString(2).split('1').length - 1
+  let count = 0
+  while (a) {
+    a &= (a - 1)
+    count++
+  }
+
+  return count
 }
 
 export { BinaryCountSetBits }