Big Number--hdu1018(数学)

#include <iostream>
#include <queue>
#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <stack>
#include <cmath>
#include <algorithm>
using namespace std;
#define N 1e7+7
#define memset(a,b) memset(a,b,sizeof(a))

int main()
{
    int T;
    scanf("%d",&T);
    while(T--)
    {
        double sum=0;
        int n;
        scanf("%d",&n);
        for(int i=1;i<=n;i++)
        {
            sum+=log10(i);
        }
        printf("%d\n",(int)(sum+1));
    }
    return 0;
}