Compilare: user.cpp: In function ‘int main()’: user.cpp:65:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<s.size();i++) ^ user.cpp:77:27: warning: array subscript has type ‘char’ [-Wchar-subscripts] val[chs[j]]=(((1<<j)&i)!=0); ^ user.cpp:82:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<s.size();i++) ^ user.cpp:94:27: warning: array subscript has type ‘char’ [-Wchar-subscripts] val[chs[j]]=(((1<<j)&i)!=0); ^