Count digits in a factorial
Easy Accuracy: 47.53% Submissions: 1144 Points: 2

Given an integer N. You have to find the number of digits that appear in its factorial, where factorial is defined as, factorial(N) = 1*2*3*4……..*N and factorial(0) = 1.

Example 1:

Input:
N = 5
Output:
3
Explanation:
5! is 120 so there are 3
digits in 120


Example 2:

Input:
N = 100
Output:
7
Explanation:
100! is 3628800â€‹ so there are
7 digits in 3628800â€‹


You don't need to read input or print anything. Your task is to complete the function facDigits() which takes an integer N as input parameter and returns the number of digits in factorial of N.

Expected Time Complexity: O(1)
Expected Space Complexity: O(1)

Constraints:
1 ≤ N ≤ 104

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