View Code of Problem 67

#include<stdio.h>
#include<math.h>
#include<string.h>
void main()
{
	int a,b,i,j,n,m,sum,x1,y1,x2,y2,x3,y3,x4,y4;
	double k1,k2;
    while(scanf("%d%d%d%d%d%d%d%d",&x1,&y1,&x2,&y2,&x3,&y3,&x4,&y4)!=EOF)
	{
		if(x1==x2&&x3==x4)
		{
			if(x1!=x3)
			printf("No\n");
			else
			printf("Yes\n");
		}
	else
	{
		k1=(x1-x2)/((y1-y2)*1.0);
		k2=(x3-x4)/((y3-y4)*1.0);
        if(k1==k2&&(y1-k1*x1)!=(y3-k2*x3))
		printf("No\n");
		else
			printf("Yes\n");
	}


	}
}