HDU 1018 Big Number

#include<iostream>
#include<cstdio>
#include<cmath>
using namespace std;
int main()
{
int n,a,i;
double sum;
scanf("%d",&n);
while(n--)
{
scanf("%d",&a);sum=1;
for(i=1;i<=a;i++) sum+=log10(i*1.0);
printf("%d\n",(int)sum);
}
return 0;
}