#include #include #include #include #include using namespace std; const double epsilon = numeric_limits().epsilon(); const numeric_limits DOUBLE; const double MIN = DOUBLE.min(); const double MAX = DOUBLE.max(); struct Point { const double x, y; }; struct Edge { const Point a, b; bool operator()(const Point& p) const { if (a.y > b.y) return Edge{ b, a }(p); if (p.y == a.y || p.y == b.y) return operator()({ p.x, p.y + epsilon }); if (p.y > b.y || p.y < a.y || p.x > max(a.x, b.x)) return false; if (p.x < min(a.x, b.x)) return true; auto blue = abs(a.x - p.x) > MIN ? (p.y - a.y) / (p.x - a.x) : MAX; auto red = abs(a.x - b.x) > MIN ? (b.y - a.y) / (b.x - a.x) : MAX; return blue >= red; } }; struct Figure { const string name; const initializer_list edges; bool contains(const Point& p) const { auto c = 0; for (auto e : edges) if (e(p)) c++; return c % 2 != 0; } template void check(const initializer_list& points, ostream& os) const { os << "Is point inside figure " << name << '?' << endl; for (auto p : points) os << " (" << setw(W) << p.x << ',' << setw(W) << p.y << "): " << boolalpha << contains(p) << endl; os << endl; } }; int main() { const initializer_list points = { { 5.0, 5.0}, {5.0, 8.0}, {-10.0, 5.0}, {0.0, 5.0}, {10.0, 5.0}, {8.0, 5.0}, {10.0, 10.0} }; const Figure square = { "Square", { {{0.0, 0.0}, {10.0, 0.0}}, {{10.0, 0.0}, {10.0, 10.0}}, {{10.0, 10.0}, {0.0, 10.0}}, {{0.0, 10.0}, {0.0, 0.0}} } }; const Figure square_hole = { "Square hole", { {{0.0, 0.0}, {10.0, 0.0}}, {{10.0, 0.0}, {10.0, 10.0}}, {{10.0, 10.0}, {0.0, 10.0}}, {{0.0, 10.0}, {0.0, 0.0}}, {{2.5, 2.5}, {7.5, 2.5}}, {{7.5, 2.5}, {7.5, 7.5}}, {{7.5, 7.5}, {2.5, 7.5}}, {{2.5, 7.5}, {2.5, 2.5}} } }; const Figure strange = { "Strange", { {{0.0, 0.0}, {2.5, 2.5}}, {{2.5, 2.5}, {0.0, 10.0}}, {{0.0, 10.0}, {2.5, 7.5}}, {{2.5, 7.5}, {7.5, 7.5}}, {{7.5, 7.5}, {10.0, 10.0}}, {{10.0, 10.0}, {10.0, 0.0}}, {{10.0, 0}, {2.5, 2.5}} } }; const Figure exagon = { "Exagon", { {{3.0, 0.0}, {7.0, 0.0}}, {{7.0, 0.0}, {10.0, 5.0}}, {{10.0, 5.0}, {7.0, 10.0}}, {{7.0, 10.0}, {3.0, 10.0}}, {{3.0, 10.0}, {0.0, 5.0}}, {{0.0, 5.0}, {3.0, 0.0}} } }; for(auto f : {square, square_hole, strange, exagon}) f.check(points, cout); return EXIT_SUCCESS; }