奋战杭电ACM（DAY12）1018

又是一道数学题，用对数求位数

Big Number

#include <iostream>#include <cmath>using namespace std;int main(){    int n,m;    double sum,digit;    while(cin >> n){    while(n>=1)    {        cin >> m;        sum=0;        for(int i=1; i<=m; i++)        {            digit=log10((double)i);//long double/double/float log10(long double/double/float)            sum += digit;        }        n-=1;        cout << (int)(sum+1) << endl;    }    }    return 0;}