Compilare: user.cpp: In function ‘int main()’: user.cpp:16:20: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(fr[v[dr]]==0) ^ user.cpp:19:17: warning: array subscript has type ‘char’ [-Wchar-subscripts] fr[v[dr]]++; ^ user.cpp:28:31: warning: array subscript has type ‘char’ [-Wchar-subscripts] while(fr[v[st]]>1){ ^ user.cpp:29:29: warning: array subscript has type ‘char’ [-Wchar-subscripts] fr[v[st]]--; nr--; ^ user.cpp:32:25: warning: array subscript has type ‘char’ [-Wchar-subscripts] fr[v[st]]--; nrc--; nr--; st++; ^