Compilare: user.cpp: In function ‘bool check(unsigned int)’: user.cpp:13:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<v[mod].size(); ++i) ^ user.cpp:14:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if( x == v[mod][i]) ^ user.cpp: In function ‘int main()’: user.cpp:25:37: 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:26:39: 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:31:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%u%u", &n, &m); ^ user.cpp:32:54: 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:36:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%u", &x); ^