Compilare: user.cpp: In function ‘void ReadPolygon()’: user.cpp:35:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &N); ^ user.cpp:39:52: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lf%lf", &polygon[i].x, &polygon[i].y); ^ user.cpp: In function ‘int main()’: user.cpp:87:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("camera.in", "r", stdin); ^ user.cpp:88:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("camera.out", "w", stdout); ^