Compilare: main.cpp: In function 'void FFT(std::vector<std::complex<double> >&)': main.cpp:21:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::complex<double> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 21 | while(n < A.size()) n <<= 1, ++e2; | ~~^~~~~~~~~~ main.cpp: In function 'vi mult(vi&, vi&)': main.cpp:62:16: warning: moving a local object in a return statement prevents copy elision [-Wpessimizing-move] 62 | return move(R); | ~~~~^~~ main.cpp:62:16: note: remove 'std::move' call main.cpp: In function 'int main()': main.cpp:87:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 87 | if(v >= R.size()) printf("0\n"); | ~~^~~~~~~~~~~