172. Factorial Trailing Zeroes

Given an integer n, return the number of trailing zeroes in n!.

Example 1:

Input:
 3

Output:
 0

Explanation:
 3! = 6, no trailing zero.

Example 2:

Input:
 5

Output:
 1

Explanation:
 5! = 120, one trailing zero.

Note: Your solution should be in logarithmic time complexity.

Solution

(1) Java

(2) Python

class Solution:
    def trailingZeroes(self, n):
        """
        :type n: int
        :rtype: int
        """
        rst = 0
        divisor = 5
        while n/divisor > 0:
            rst += int(n/divisor)
            divisor *= 5
        return rst

(3) Scala