View Code of Problem 67

#include<iostream>
#include<cmath>

using namespace std;

int main(){
	double x1;
	double x2;
	double x3;
	double x4;
	double y1;
	double y2;
	double y3;
	double y4;
	while(cin>>x1>>y1>>x2>>y2>>x3>>y3>>x4>>y4){
		if(x1==x2&&x3==x4){
			if(x1==x3){
				cout<<"Yes"<<endl;
			} else {
				cout<<"No"<<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;
} 
/*
Main.cc: In function 'int main()':
Main.cc:23:4: error: 'k1' was not declared in this scope
    k1=(y2-y1)/(x2-x1);
    ^~
Main.cc:23:4: note: suggested alternative: 'y1'
    k1=(y2-y1)/(x2-x1);
    ^~
    y1
Main.cc:24:4: error: 'k2' was not declared in this scope
    k2=(y4-y3)/(x4-x3);
    ^~
Main.cc:24:4: note: suggested alternative: 'y2'
    k2=(y4-y3)/(x4-x3);
    ^~
    y2
Main.cc:25:4: error: 'b1' was not declared in this scope
    b1=y1-k1*x1;
    ^~
Main.cc:25:4: note: suggested alternative: 'y1'
    b1=y1-k1*x1;
    ^~
    y1
Main.cc:26:4: error: 'b2' was not declared in this scope
    b2=y3-k2*x3;
    ^~
Main.cc:26:4: note: suggested alternative: 'y2'
    b2=y3-k2*x3;
    ^~
    y2
*/