View Code of Problem 67

#include<stdio.h>
#include <string.h>
#include <math.h>
int main(){
	int x1,y1,x2,y2;
	int x3,y3,x4,y4;
	double tn1,tn2;
	while(scanf("%d%d%d%d",&x1,&y1,&x2,&y2)!=EOF){
		scanf("%d%d%d%d",&x3,&y3,&x4,&y4);
		if(x1!=x2&&x3!=x4){
			if((y2-y1)/(x2-x1)==(y4-y3)/(x4-x3)){
				if(y1-x1*(y2-y1)/(x2-x1)==y3-x3*(y4-y3)/(x4-x3))
				printf("Yes\n");
				else
				printf("No\n");
			}
			else
			printf("Yes\n");
		}
		else if(x1==x2&&x3==x4){
			if(x1==x3)
			printf("Yes\n");
			else
			printf("No\n");
		}
		else{
		printf("Yes\n");
		}
	}
	printf("\n");
	return 0;
}