Count Decimal Zeros at the End of a Factorial
Company: Google
Role: Software Engineer
Category: Coding & Algorithms
Difficulty: medium
Interview Round: Other
### Problem
Return the number of trailing decimal zeros in `n!`, the factorial of `n`. Use the convention `0! = 1`.
```cpp
int trailingZeroes(int n);
```
### Examples
```text
Input: n = 25
Output: 6
```
```text
Input: n = 100
Output: 24
```
### Constraints
- `0 <= n <= 10000`.
### Optional follow-up
Can you solve it in logarithmic time?
Overview: Count factorial trailing zeros through repeated factor-of-five quotients without constructing the factorial.
Community answers
Answer by Coderka14
#include
using namespace std;
class Solution
{
public:
int trailingZeroes(int n)
{
int count = 0;
while (n > 0)
{
n /= 5;
count += n;
}
return count;
}
};