int main () { float r,h,v,m; scanf ("%f %f", &r, &h); if (h>=0 && h<=5 && r<=5 && r>=0) { double v=3.14159*r*r*h/3; double m=7.8*1000*v; printf ("%.6lf %.4lf", v, m);//printf的格式!!! } else printf ("problem"); return 0; }