leetcode---Factorial Trailing Zeroes

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

Note: Your solution should be in logarithmic time complexity.

class Solution {
public:
int trailingZeroes(int n)
{
if(n == 0)
return 0;
int c5 = 0;
while(n)
{
c5 += n/5;
n /= 5;
}
return c5;
}
};