直线的正交/平行的判定

#include <iostream>
using namespace std;

class Point
{
public:
    double x, y;
    Point()
    {
    }
    Point(double x, double y)
    {
        (*this).x = x;
        (*this).y = y;
    }

    double operator^(const Point &p) const //叉乘
    {
        return x * p.y - y * p.x;
    }

    double operator*(const Point &p) const //点乘
    {
        return x * p.x + y * p.y;
    }
    Point operator-(const Point &p) const
    {
        return Point(x - p.x, y - p.y);
    }
};

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);

    int q;
    cin >> q;
    Point p[4];
    double x, y;
    while (q--)
    {
        for (int i = 0; i < 4; ++i)
        {
            cin >> x >> y;
            p[i] = Point(x, y);
        }

        if (!((p[1] - p[0]) * (p[3] - p[2])))
            cout << 1 << endl;
        else if (!((p[1] - p[0]) ^ (p[3] - p[2])))
            cout << 2 << endl;
        else
            cout << 0 << endl;
    }
}