Compilare: user.cpp: In function ‘int In_hash(int)’: user.cpp:17:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < V[x % mod].size(); ++ i) ^ user.cpp: In function ‘void read()’: user.cpp:24:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("muzica.in", "r", stdin); ^ user.cpp:25:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("muzica.out", "w", stdout); ^ user.cpp:26:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^ user.cpp:27:58: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld %lld %lld %lld %lld", &a, &b, &c, &d, &e); ^ user.cpp: In function ‘void solve()’: user.cpp:43:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &x); ^