Compilare: user.cpp: In function ‘int main()’: user.cpp:87:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < Useful.size(); i++) ^ user.cpp:95:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < Useful.size(); i++) { ^ user.cpp:98:46: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (w_right + 1 < Useful.size()) { ^ user.cpp:120:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < Useful.size(); i++) ^ 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("copaci3.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("copaci3.out","w",stdout); ^ user.cpp:69:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &D); ^ user.cpp:71:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &Height[i]); ^