How should I practice Factorial Trailing Zeroes?

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Factorial Trailing Zeroes

Microsoft● MediumNEW GRADONSITE INTERVIEW

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Problem statement

Given a nonnegative integer n, return the number of trailing zeroes in the decimal representation of n!.

Function

trailingZeroes(n: int) → int

Examples

Example 1

n = 5return = 1

5! = 120, which ends with one zero.

Example 2

n = 30return = 7

The factors 5, 10, 15, 20, 25, and 30 contribute six factors of five, and 25 contributes one additional factor.

Constraints

0 <= n <= 10^9
0! = 1