Untitled

 
const ld EPS = 1e-6;
 
typedef ld T;
bool eq(T a, T b){ return abs(a - b) <= EPS; }
struct point{
    T x, y;
    int id;
    point(T x=0, T y=0): x(x), y(y){}
    point operator+(const point &o) const{ return {x + o.x, y + o.y}; }
    point operator-(const point &o) const{ return {x - o.x, y - o.y}; }
    point operator*(T t) const{ return {x * t, y * t}; }
    point operator/(T t) const{ return {x / t, y / t}; }
    T operator*(const point &o) const{ return x * o.x + y * o.y; } // dot product
    T operator^(const point &o) const{ return x * o.y - y * o.x; } // cross product
};
 
ld dist(point a, point b) {
    point d = a - b;
    return sqrt(d * d);
}