Compilare: user.cpp: In function ‘int main()’: user.cpp:32:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < s1.size (); i++) { ^ user.cpp:33:16: warning: array subscript has type ‘char’ [-Wchar-subscripts] H[s1[i]].push_back (i + 1); ^ user.cpp:35:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < s2.size (); i++) { ^ user.cpp:36:20: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (H[s2[i]].empty ()) { ^ user.cpp:40:27: warning: array subscript has type ‘char’ [-Wchar-subscripts] v[i + 1] = H[s2[i]].front (); ^ user.cpp:41:16: warning: array subscript has type ‘char’ [-Wchar-subscripts] H[s2[i]].pop_front (); ^ user.cpp:44:21: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (!H[s1[i]].empty ()) { ^