Compilare: user.cpp: In function ‘int main()’: user.cpp:27:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < s.size(); i++) ^ user.cpp:28:25: warning: array subscript has type ‘char’ [-Wchar-subscripts] cnt[s[i]]++; ^ user.cpp:47:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < s.size(); i++) { ^ user.cpp:49:32: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (change[s[i]] == s2[i]) continue; ^ user.cpp:51:32: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (change[s[i]] == 0) change[s[i]] = s2[i]; ^ user.cpp:51:51: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (change[s[i]] == 0) change[s[i]] = s2[i]; ^