Compilare: user.cpp: In function ‘int main()’: user.cpp:25:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(a[c].size()<p)cout<<-1<<endl; ^ user.cpp:10:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("costuri.in","r",stdin); ^ user.cpp:11:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("costuri.out","w",stdout); ^