Compilare: user.cpp: In function ‘int main()’: user.cpp:17:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<s.length(); i++) ^ user.cpp:22:39: warning: array subscript has type ‘char’ [-Wchar-subscripts] while (k>=0) { if (!e[s[k]]) v.push_back(make_pair(s[i],q[i])); e[s[k]]=true; s[k]=q[i]; goto l; } ^ user.cpp:22:83: warning: array subscript has type ‘char’ [-Wchar-subscripts] while (k>=0) { if (!e[s[k]]) v.push_back(make_pair(s[i],q[i])); e[s[k]]=true; s[k]=q[i]; goto l; } ^ user.cpp:28:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<v.size(); i++) ^