zoj 1242 Carbon Dating

#include <iostream>#include <math.h>#include <stdio.h>using namespace std;double d, w, age, temp;int main(){    int num=1;    while (scanf("%lf %lf", &w, &d), w&&d)    {        printf("Sample #%dn", num++);        temp = d/w/810.0;        temp = log(temp);        age = temp/log(0.5)*5730.0;        if (age < 10000)        { temp = int(age/100.0+0.5); age = temp*100.0;        }        else        { temp = int(age/1000.0+0.5); age = temp*1000.0;        }        printf("The approximate age is %.lf years.nn", age);    }    return 0;}