求一个能算三点共线和两点间距离的c语言程序

Question

求一个能算三点共线和两点间距离的c语言程序

Answer 1

#include
#include
#include
int main()
{
struct dian
{
float x;
float y;
}a,b,c;
float m;
int k;
printf("计算两点距离请输入2,判断三点共线请按3\n");
scanf("%d",&k);
if(k==2)
{
printf("请输入第一个点的坐标\n");
scanf("%f%f",&a.x,&a.y);
printf("请输入第二个点的坐标\n");
scanf("%f%f",&b.x,&b.y);
m=sqrt((a.x-b.x)*(a.x-b.x)+(a.y-b.y)*(a.y-b.y));
printf("distance=%f\n",m);
}
else if(k==3)
{
printf("请输入第一个点的坐标\n");
scanf("%f%f",&a.x,&a.y);
printf("请输入第二个点的坐标\n");
scanf("%f%f",&b.x,&b.y);
printf("请输入第三个点的坐标\n");
scanf("%f%f",&c.x,&c.y);
{
if(((b.y-a.y)/(b.x-a.x))==((c.y-a.y)/(c.x-a.x)))
printf("这三点共线\n");
else
printf("这三点不共线\n");
}
}
else
{
printf("system wrong\n");
}
system ("pause");
return 0;
}