View Code of Problem 67

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
int main (){
	double x1, y1, x2, y2, x3, y3, x4, y4;
	while(~scanf("%lf%lf%lf%lf", &x1, &y1, &x2, &y2)){
		scanf("%lf%lf%lf%lf", &x3, &y3, &x4, &y4);
		if(x1!=x2&&x3!=x4){
			double k1 = (y2-y1)/(x2-x1);
			double k2 = (y4-y3)/(x4-x3);
			if(k1!=k2){
				printf("Yes\n");
			}else if(y1-k1*x1!=y3-k2*x3){
				printf("No\n");
			}else{
				printf("Yes\n");
			}
		}else if(x1==x2&&x3==x4&&x1!=x3){
			printf("No\n");
		}else{
			printf("Yes\n");
		}
	}

	return 0;
}