Compilare: user.cpp: In function ‘int main()’: user.cpp:52:20: warning: array subscript has type ‘char’ [-Wchar-subscripts] nr[s[j]]+=(1<<j); ^ user.cpp:69:20: warning: array subscript has type ‘char’ [-Wchar-subscripts] nr[s[j]]+=(1<<j); ^ user.cpp:74:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=0; j<H[cod].size() && !ok; ++j) ^