Method PT

Dynamic Programming Optimizations/Persistent CHT.cpp:3–3

struct PT {
  int x, y;
  PT(int x = 0, int y = 0): x(x), y(y) {}
  friend ll dot(PT &a, PT &b) {
    return 1ll * a.x * b.x + 1ll * a.y * b.y;
  }