View Code of Problem 67

#include <stdio.h>

int main ()
{
	int a[2],b[2],c[2],d[2];
	double y1,y2,b1,b2;
	
	while (scanf ("%d%d%d%d",&a[0],&a[1],&b[0],&b[1])!=EOF){
		scanf ("%d%d%d%d",&c[0],&c[1],&d[0],&d[1]);
		if (b[0]==a[0]){
			if (d[0]==c[0]&&a[0]!=c[0]) printf ("No\n");
			else printf ("Yes\n");
		}
		else {
			y1 = 1.0*(b[1]-a[1])/(b[0]-a[0]);
		    y2 = 1.0*(d[1]-c[1])/(d[0]-c[0]);
		    b1 = a[1]-a[0]*y1;
		    b2 = c[1]-c[0]*y2;
		    if (y1==y2&&b1!=b2) printf ("No\n");
		    else printf ("Yes\n");
		}
	}
	return 0;
}