Week9 练习

1，

#include "stdio.h"void sayhello(){printf("hello");}void main(){sayhello();}

2,

#include "stdio.h"  #include <math.h>  double qiu(double x,double y,double z){ return sqrt(x*x+y*y+z*z);}int main(){double x,y,z,a;scanf("%lf,%lf,%lf",&x,&y,&z);printf("x=%f,y=%f,z=%f,a=%f\n",x,y,z,qiu(x,y,z));}

3,