HDU 1060 Leftmost Digit 数学题

http://www.cppblog.com/LeoW/archive/2012/03/08/167427.html

#include<stdio.h>
#include<string.h>
#include<math.h>
#define lld __int64
int main()
{
    int i, j, cas;
    int n;
    scanf("%d", &cas);
    while(cas--)
    {
        scanf("%d", &n);
        double sum1 = n*log10(n*1.0);
        lld sum2 = (lld) sum1;
        sum1 -= sum2;
        printf("%d\n", (int)pow(10.0, (double)sum1));
    }
    return 0;
}