week 9 热身

写一个求变量平方和的平方根函数,

/* Note:sqrt*/
#include "stdio.h"
#include"math.h"

double  getZ(double x,double y,double z){
	double r;
	r=sqrt(x*x+y*y+z*z);
	return r;
	/*  get easier:return sqrt(x*x+y*y+z*z);*/
    
}
int  main()
{double x,y,z,w;
	x=3;
	y=4;
	z=5;
	w=getZ(x,y,z);
	printf("x=%f,y=%f.z=%f,w=%f",x,y,z,getZ(x,y,z));
	
}

无参数无返回值

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