Compilare: main.cpp: In function 'void ord_chars()': main.cpp:27:14: warning: array subscript has type 'char' [-Wchar-subscripts] ord[i]=cnt; cnt++; ^ main.cpp:30:14: warning: array subscript has type 'char' [-Wchar-subscripts] ord[c]=cnt; cnt++; ^ main.cpp:33:14: warning: array subscript has type 'char' [-Wchar-subscripts] ord[c]=cnt; cnt++; ^ main.cpp: In function 'std::vector<std::complex<double> > multiply(const std::vector<std::complex<double> >&, const std::vector<std::complex<double> >&)': main.cpp:80:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(n<(a.size()+b.size()) ){ ~^~~~~~~~~~~~~~~~~~~~ main.cpp: In function 'void build_pol(std::vector<std::complex<double> >&, std::vector<std::complex<double> >&, std::__cxx11::string&, std::__cxx11::string&)': main.cpp:97:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<t.length(); i++){ ~^~~~~~~~~~~ main.cpp:98:45: warning: array subscript has type 'char' [-Wchar-subscripts] double ang=2*PI/(26*2+10)*(ord[t[i] ]); ^ main.cpp:106:45: warning: array subscript has type 'char' [-Wchar-subscripts] double ang=2*PI/(26*2+10)*(ord[s[i] ]); ^ main.cpp: In function 'int32_t main()': main.cpp:123:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<s.length(); i++){ ~^~~~~~~~~~~ main.cpp:138:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=((int)s.length())-1; i<(t.length()); i++){ ~^~~~~~~~~~~~~