View Code of Problem 67

#include<stdio.h>
#include<string.h>
#include "math.h"
int main()
{
	float x1,y1,x2,y2,x3,y3,x4,y4,k1,k2,b1,b2;
	while(scanf("%f%f%f%f%f%f%f%f",&x1, &y1, &x2, &y2, &x3, &y3, &x4, &y4)!=EOF)
	{
		if(x1==x2 && x3==x4)
		{
			if(x1==x3)
			   printf("Yes\n");
			else
			   printf("No\n");
		}
		else
		{
		k1=(y1-y2)/(x1-x2);
		k2=(y3-y4)/(x3-x4);
		b1=y1-k1*x1;
		b2=y3-k2*x3;
		
	    if(k1==k2 &&  b1!=b2)
		  printf("No\n");
		else 
		  printf("Yes\n");
		}
		
	}
	return 0;
}