Compilare: user.cpp: In function ‘int main()’: user.cpp:34:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<c.size();i++) ^ user.cpp:35:19: warning: array subscript has type ‘char’ [-Wchar-subscripts] v[c[i]]='a'+i; ^ user.cpp:41:34: warning: array subscript has type ‘char’ [-Wchar-subscripts] s[i][j]=v[s[i][j]]; ^ user.cpp:47:39: warning: array subscript has type ‘char’ [-Wchar-subscripts] fout << char(w[s[i][j]]); ^