Compilare: user.cpp: In function ‘int main()’: user.cpp:28:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < s.size(); i++) ^ user.cpp:29:25: warning: array subscript has type ‘char’ [-Wchar-subscripts] cnt[s[i]]++; ^ user.cpp:50:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < s.size(); i++) { ^ user.cpp:52:32: warning: array subscript has type ‘char’ [-Wchar-subscripts] change[s[i]] = s2[i]; ^ user.cpp:56:32: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (change[s[i]] == s2[i]) continue; ^ user.cpp:58:32: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (change[s[i]] == 0 && !changed[s2[i]]) { ^ user.cpp:58:56: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (change[s[i]] == 0 && !changed[s2[i]]) { ^ user.cpp:59:32: warning: array subscript has type ‘char’ [-Wchar-subscripts] change[s[i]] = s2[i]; ^ user.cpp:60:34: warning: array subscript has type ‘char’ [-Wchar-subscripts] changed[s2[i]] = true; ^