Compilare: user.cpp: In function ‘bool normal()’: user.cpp:20:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int z=0; z<t[i].length(); z++) ^ user.cpp:21:19: warning: array subscript has type ‘char’ [-Wchar-subscripts] f1[t[i][z]]++; ^ user.cpp:22:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int z=0; z<=t[j].length(); z++) ^ user.cpp:23:19: warning: array subscript has type ‘char’ [-Wchar-subscripts] f2[t[j][z]]++; ^ user.cpp: In function ‘int main()’: user.cpp:63:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0; i<v.size(); i++) ^