View Code of Problem 67

#include<iostream>
using namespace std;
int main()
{
	float x1, y1, x2, y2;
	float 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" << "\n";
			}
			else {
				cout << "No" << "\n";
			}
		}
		else if (x1 == x2 && x3 != x4) {
			cout << "Yes" << "\n";
		}
		else if (x1 != x2 && x3 == x4) {
			cout << "Yes" << "\n";
		}
		else if ((y2 - y1) / (x2 - x1) == (y4 - y3) / (x4 - x3)) {
			if ((y3 - y2) / (x3 - x2) == (y2 - y1) / (x2 - x1)) {
				cout << "Yes" << "\n";
			}
			else {
				cout << "No" << "\n";
			}
		}
		else {
			cout << "Yes" << "\n";
		}
	}
	return 0;
}