View Code of Problem 67

#include <iostream>
#include <cstdio>
using namespace std;
int main(){
    double x1,y1,x2,y2,x3,y3,x4,y4,k1,k2,b1,b2;
    while(cin>>x1>>y1>>x2>>y2>>x3>>y3>>x4>>y4){
        if(x1==x2&&x3==x4){
            if(x1==x3)
                cout<<"No"<<endl;
            else
                cout<<"Yes"<<endl;
        }
        else{
            k1=(y2-y1)/(x2-x1);
            k2=(y4-y3)/(x4-x3);
            b1=y1-k1*x1;
            b2=y3-k2*x3;
            if(k1==k2&&b1!=b2)
                cout<<"No"<<endl;
            else
                cout<<"Yes"<<endl;
        }
    }
    return 0;
}