Least significant non-zero digit of a factorial

by jairajdesai

HTML

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.2.0/jquery.min.js"></script>
<div id="display">

</div>
<div id="display2">

</div>
<input type="text" value="" id="number">
<input type="submit" id="submit">

JavaScript

$(document).ready(function() {
  $('#submit').click(function() {
    var n = $('#number').val();
    get_result(n);
  });
});

function get_result(n) {
  var factorial = 1;
  var factorial2 = 1;
  for (i = 1; i <= n; i++) {
    factorial = factorial * i;
  }
  var count_5 = 0;
  for (j = 1; j <= n; j++) {
    if (j % 5 != 0) {
      factorial2 = factorial2 * (j % 10);
      factorial2 = factorial2 % 10;
    } else if (j % 5 == 0) {
      count_5 = 1;
    }
  }
  if (count_5 == 1) {
    factorial2 = factorial2 * 5;
  }
  console.log(factorial2);
  factorial2 = factorial2.toString();
  var digit = 0;
  for (i = 0; i < factorial2.length; i++) {
    if (factorial2[i] != '0') {
      digit = factorial2[i];
    }
  }
  $('#display').text("Factorial of " + n + " is " + factorial);
  $('#display2').text("Least significant digit of Factorial of " + n + " is " + digit);
}