Leetcode: Factorial Trailing Zeroes

Question

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

Note: Your solution should be in logarithmic time complexity.

Credits:

Special thanks to @ts for adding this problem and creating all test cases.

Show Tags

Show Similar Problems

Solution

Analysis

Count how many factor 5 in n!

Code

[code]class Solution(object):
    def trailingZeroes(self, n):
        """
        :type n: int
        :rtype: int
        """

        res = 0
        while n!=0:
            res = res + n/5
            n /= 5

        return res