View Code of Problem 67

#include<stdio.h>
void main()
{
	float x1,y1,x2,y2,x3,y3,x4,y4;
	float k1,k2,b1,b2;
	while(scanf("%f%f%f%f%f%f%f%f",&x1,&y1,&x2,&y2,&x3,&y3,&x4,&y4)!=EOF)
	{
		k1=(y2-y1)/(x2-x1);
		k2=(y4-y3)/(x4-x3);
		b1=y1-k1*x1;
		b2=y3-k2*x3;
		if(x1==x2&&x3==x4)
		{
			if(x1==x3)
				printf("Yes\n");
			else
				printf("No\n");
		}
		else
		{
			if(k1==k2&&b1!=b2)
				printf("No\n");
			else
				printf("Yes\n");
		}
	}
}