Compilare: user.cpp: In function ‘void FFT::FFT(int, FFT::Complex*, FFT::Complex*)’: user.cpp:79:19: warning: unused variable ‘k’ [-Wunused-variable] int i, j, k; ^ user.cpp: In function ‘std::vector<FFT::Complex> FFT::Multiply(std::vector<FFT::Complex>, std::vector<FFT::Complex>)’: user.cpp:115:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (A.size() < dim) A.pb({0, 0}); ^ user.cpp:116:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (B.size() < dim) B.pb({0, 0}); ^ user.cpp:133:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < C.size(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:194:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < C.size(); i++) ^ user.cpp: In instantiation of ‘std::vector<_RealType> poly_multiply(std::vector<_RealType>, std::vector<_RealType>) [with T = int]’: user.cpp:192:31: required from here user.cpp:149:36: 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] for (i = 0; i < A.size(); i++) AA.pb({A[i], 0.00}); ^ user.cpp:150:36: 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] for (i = 0; i < B.size(); i++) BB.pb({B[i], 0.00}); ^ user.cpp:171:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bacterii2.in","r",stdin); ^ user.cpp:172:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bacterii2.out","w",stdout); ^ user.cpp:174:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &t); ^ user.cpp:178:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:180:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &x); ^ user.cpp:184:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:186:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &x); ^