HDU 1018 Big Number

这种题目考的是数学功底啊，用脚趾都能想到，任何一个数的长度等于它对10求对数加1；

而log10(n!)=log10(1*2*3*4*5********n)=log10(1)+log10(2)+............+log10(n);

#include<map>
#include<set>
#include<queue>
#include<cmath>
#include<vector>
#include<cstdio>
#include<string>
#include<cstring>
#include<cstdlib>
#include<iostream>
#include<algorithm>
#define  inf 0x0f0f0f0f

using namespace std;

const double pi=acos(-1.0);
const double eps=1e-8;
typedef pair<int,int>pii;

double get_len(int n)
{
    double sum=0.0;
    for (int i=1;i<=n;i++)
    {
        sum+=double(log10(i+0.0));
    }
    return sum;
}

int main()
{
    //freopen("in.txt","r",stdin);

    int t,n;
    scanf("%d",&t);
    while (t--)
    {
        scanf("%d",&n);
        int len=int(get_len(n))+1;
        printf("%d
",len);
    }
    //fclose(stdin);
    return 0;
}