Count Trailing Zeros in Factorial of a Number | Coding Interview | Maths | Python 🐍 & C++
4 min readJul 22, 2022
This is the second program under the mathematics category that can be asked during the initial phase of your interview. It is a simple problem to code if you know basic maths; for example, in this case, you need to know how we get zeros in a factorial of a number (in what conditions).
If you are preparing for an interview, consider solving these problems.
Let’s begin.
Definition
Given a positive integer n, we have to find the number of trailing zeros of its factorial, n!.
The factorial of a number n is the product of all the numbers from n to 1.
n! = n x (n-1) x (n-2) x … 3 x 2 x 1
For example, the factorial of 6 ( 6 x 5 x 4 x 3 x 2 x 1) is 720, and the number of trailing zeros is 1.
Example 1:
Input: n = 5
Output: 1Explanation: The factorial of 5 (5!) is 120, hence the number of trailing zeros is 1.
