Compilare: user.cpp: In function ‘int64_t getArea(const std::vector<Point>&)’: user.cpp:24:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 1; i < P.size(); i++) Area += llabs(Det(P[0], P[i - 1], P[i])); ^ user.cpp: In function ‘std::vector<Point> getHull(std::vector<Point>&)’: user.cpp:35:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 2; i < P.size(); i++) { ^ user.cpp: In function ‘int main()’: user.cpp:66:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("gradina.in", "r", stdin); ^ user.cpp:67:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("gradina.out", "w", stdout); ^ user.cpp:69:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &N); ^ user.cpp:71:37: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &P[i].x, &P[i].y); ^