Compilare: user.cpp: In function ‘long long int nrseq(int)’: user.cpp:25:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (H.size() > u) ^ user.cpp: In function ‘void read()’: user.cpp:13:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("secv5.in", "r", stdin); ^ user.cpp:14:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d", &n, &l, &u); ^ user.cpp:16:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%ud", &w[i]); ^ user.cpp: In function ‘void write()’: user.cpp:44:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("secv5.out", "w", stdout); ^