-
-
Save benloong/89aeb4a9c8dc27c3354f653d2ada139f to your computer and use it in GitHub Desktop.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| // http:// stackoverflow.com/questions/23202489/how-does-this-code-find-the-number-of-trailing-zeros-from-any-base-number-factor | |
| // https://comeoncodeon.wordpress.com/2010/02/17/number-of-zeores-and-digits-in-n-factorial-in-base-b/ | |
| function zeroes (base, number) { | |
| var noz = Number.MAX_VALUE; | |
| // Now we can break the Base B as a product of primes : | |
| // B = a^p1 * b^p2 * c^p3 * … | |
| //Then the number of trailing zeroes in N factorial in Base B is given by the formulae | |
| // min{1/p1(n/a + n/(a*a) + ….), 1/p2(n/b + n/(b*b) + ..), ….}. | |
| var j = base; | |
| for (var i = 2; i <= base; i++) { | |
| if (j % i === 0) { | |
| var p = 0; | |
| while (j % i === 0) { | |
| j = j / i; | |
| p++; | |
| } | |
| var c = 0; | |
| var z = Math.floor(number / i); | |
| while (z > 0) { | |
| c += z; | |
| z = Math.floor(z / i); | |
| } | |
| noz = Math.min(noz, Math.floor(c / p)) | |
| } | |
| } | |
| return noz; | |
| } |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment