HOJ 2076 Series Determination

#include <stdio.h>

int main()
{
double f[8], a, b, c;

while (scanf("%lf %lf %lf",&f[0],&f[1],&f[2])!=EOF)
{
c = f[0];
a = ( (f[2] + f[0]) / 2) - f[1];
b = f[1] - f[0] - a;
f[3] = a * 9 + b * 3 + c;
f[4] = a * 16 + b * 4 + c;
f[5] = a * 25 + b * 5 + c;
printf("%.0lf %.0lf %.0lf\n",f[3], f[4], f[5]);
}

return 0;
}