大数阶乘(位数)

#include <stdio.h>
#include <math.h>

int BigNumFactorial(int InputOrderMultiplier)
{
    int i;
    double Result = 0;
    for(i = 1;i <= InputOrderMultiplier;i ++)
    {
        Result += log10(i);
    }
    return (int)Result+1;
}

int main()
{
    int InputOrderMultiplier = 19999;
    int Result = BigNumFactorial(InputOrderMultiplier);
    printf("%d\n",Result);
    return 0;
}