My task is to complete the function digitsInFactorial() that takes N as input parameter and returns number of digits in factorial of N.

class Solution{
    public:
    int digitsInFactorial(int N)
    {
        long long fact=1;
        for(int i=2;i<=N;i++){
            fact*=i;
        }
     int res=0;
     while(fact>0){
         res++;
         fact/=10;
     }
     return res;
    }
};      in this code 1st I find the factorial ,after that I have to find trailing zeros in the factorial . but , it is given incorrect output for the larger number.