View Code of Problem 67

#include<iostream>
using namespace std;
int main() {
	
	double a[8];
	double k1, k2;
	bool f1=false,f2=false;
	while (true) {
		for (int i = 0; i < 8; i++)
		{
			cin >> a[i];
		}
		if (a[2] - a[0] == 0) {
			f1 = true;
		}
		if (a[6] - a[4] == 0) {
			f2 = true;
		}
		if(!f1)k1 = (a[3] - a[1]) / (a[2] - a[0]);
		if(!f2)k2 = (a[7] - a[5]) / (a[6] - a[4]);
		if(!f1&&!f2){
			if (k1 == k2) {
				cout << "No" << endl;
			}
			else {
				cout << "Yes" << endl;
			}
		}
		else if (f1 && f2) {
			cout << "No" << endl;
		}
		else {
			cout << "Yes" << endl;
		}
	
	}
}