View Code of Problem 67

#include<bits/stdc++.h>
using namespace std;
int main()
{
   int x1,y1,x2,y2,x3,y3,x4,y4;
   while(cin>>x1>>y1>>x2>>y2)
   {
   	cin>>x3>>y3>>x4>>y4;
   	if(x1==x2&&x3==x4)
   	{
   		if(x1==x3)
   		cout<<"Yes"<<endl;
   		else
   		cout<<"No"<<endl;
	   
	}else if(x1 != x2&&x3!=x4){
			
			double k1,k2;
			k1 = (y2-y1)*1.0/(x2-x1);
			k2 = (y4-y3)*1.0/(x4-x3);
			if(k1 != k2){
				cout<<"Yes"<<endl;
			}
			else{
				if((y1-k1*x1)==(y3-k2*x3)){
					cout<<"Yes"<<endl;
				}
				else{
					cout<<"No"<<endl;
				}
			}
			 
		}
		else{
			cout<<"Yes"<<endl;
		}
	}
	return 0;
}