Compilare: user.cpp: In function ‘std::vector<int> mult(std::vector<int>, std::vector<int>)’: user.cpp:53:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(n_<a.size()+b.size())n_=n_*2; ~~^~~~~~~~~~~~~~~~~~ user.cpp:57:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(a.size()>i)a_.push_back({a[i],0}); ~~~~~~~~^~ user.cpp:57:44: warning: narrowing conversion of ‘a.std::vector<_Tp, _Alloc>::operator[]<int, std::allocator<int> >(((std::vector<int>::size_type)i))’ from ‘__gnu_cxx::__alloc_traits<std::allocator<int> >::value_type {aka int}’ to ‘double’ inside { } [-Wnarrowing] if(a.size()>i)a_.push_back({a[i],0}); ^ user.cpp:61:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(b.size()>i)b_.push_back({b[i],0}); ~~~~~~~~^~ user.cpp:61:44: warning: narrowing conversion of ‘b.std::vector<_Tp, _Alloc>::operator[]<int, std::allocator<int> >(((std::vector<int>::size_type)i))’ from ‘__gnu_cxx::__alloc_traits<std::allocator<int> >::value_type {aka int}’ to ‘double’ inside { } [-Wnarrowing] if(b.size()>i)b_.push_back({b[i],0}); ^ user.cpp: In function ‘int main()’: user.cpp:98:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("chimichangas.in","r",stdin); ^ user.cpp:99:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("chimichangas.out","w",stdout); ^ user.cpp:101:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i%i",&n,&k); ^ user.cpp:102:42: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(int i=1;i<=n;i++){scanf("%i",&cal[i]);there[cal[i]]++;c=max(c,cal[i]);} ^ user.cpp:109:15: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i",&q); ^ user.cpp:113:15: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i",&w); ^