Compilare: user.cpp: In function ‘bool findH(POINT2D)’: user.cpp:39:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < H[get_key(p)].size(); ++i) ^ user.cpp: In function ‘int main()’: user.cpp:78:12: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] else if (points[i].second - points[j].second == 0) ^