Eroare de compilare: main.cpp: In function 'long long int det(Point, Point, Point)': main.cpp:6:69: error: 'cross' was not declared in this scope long long det(Point a, Point b, Point c) { return cross(b - a, c - a); } ^ main.cpp: In lambda function: main.cpp:27:41: error: 'cross' was not declared in this scope long long c = cross(a.first, b.first); ^ main.cpp: In function 'int main()': main.cpp:38:78: error: 'cross' was not declared in this scope while (hull.size() >= 2 && cross(hull.end()[-2] - p, hull.end()[-1] - p) <= 0) ^ main.cpp:42:74: error: 'cross' was not declared in this scope while (hull.size() >= 2 && cross(hull.end()[-1] - hull.end()[-2], p) <= 0) ^ Non zero exit status: 1