Calculate Attempts until Kaprekar's Constant from a 4-digit Integer

README.md

Get Attempts until Kaprekar's Constant

Given a 4-digit integer to the function, calculate the number of attempts until it reaches kaprekar's constant i.e. 6174

Few Examples

1. KaprekarsConstant(8) // 6
2. KaprekarsConstant(1324) // 3
3. KaprekarsConstant(3322) // 4

kaprekar-constant.js

var numOfAttempts = 0;
function addRemainingZeros(number) {
	var remaining = 4 - number.length;
	for(var i = 0; i < remaining; i++) number += '0';
	return number;
}
function KaprekarsConstant(num) {
  var numAsString = num + ''; // convert integer to string
  if (numAsString.length < 4) {
    numAsString = addRemainingZeros(numAsString);
  }
  numOfAttempts += 1;
  var aesc = parseInt(numAsString.split('').sort(function(a, b) { return a - b; }).join(''));
  var desc = parseInt(numAsString.split('').sort(function(a, b) { return b - a; }).join(''));
  var substract = desc > aesc ? desc - aesc : aesc - desc;
  return substract === 6174 ? countOfAttempts : KaprekarsConstant(substract);
}