struct Point
{
  int x, y;
};
typedef struct
{
  Point p;
  Point d;
} Line, Rect;
Point findIntersection(Line l1, Line l2)
{
  int T1, T2;
  T2 = (l2.d.x*(l1.p.y-l2.p.y) + l2.d.y*(l2.p.x-l1.p.x))/(l1.d.x*l2.d.y - l1.d.y*l2.d.x);
  T1 = (l1.p.x+l1.d.x*T2-l2.p.x)/l2.d.x;
  if (T1>0 && 0<T2<1) {
    return {l2.p.x+l2.d.x*T1, l2.p.y+l2.d.y*T1};
  }
}
Point getRectPoint(Rect r, int n)
{
  switch (n) {
    case 0: return {r.p.x, r.d.y};
    case 1: return r.d;
    case 2: return r.p;
    case 3: return {r.d.x, r.p.y};
  }
}
int main()
{
  Point p1 = {0, 0};
  Point p2 = {10, 10};
  Line  l1 = {p1, p2};
  Line  l2 = {p2, p1};
  findIntersection(l1, l2);
  return 0;
}