Compilare: user.cpp: In member function ‘void Tree2d::add_aib(std::vector<int>&, int, int)’: user.cpp:95:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (pos < work.size()) { ^ user.cpp: In function ‘int main()’: user.cpp:205:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < Points.size(); i++) ^ user.cpp:189:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("photoshop.in","r",stdin); ^ user.cpp:190:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("photoshop.out","w",stdout); ^ user.cpp:192:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &m); ^ user.cpp: In member function ‘void op::read()’: user.cpp:122:39: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &type, &a, &b); ^ user.cpp:124:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &c, &d); ^