Compilare: user.cpp: In function ‘int main()’: user.cpp:30:30: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(exista[s[nr_s]]) ^ user.cpp:36:35: warning: array subscript has type ‘char’ [-Wchar-subscripts] exista[s[nr_s]]=0; ^ user.cpp:42:32: warning: array subscript has type ‘char’ [-Wchar-subscripts] else exista[s[nr_s]]=1; ^ user.cpp:47:30: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(exista[s[nr_s]]) ^ user.cpp:53:35: warning: array subscript has type ‘char’ [-Wchar-subscripts] exista[s[nr_s]]=0; ^ user.cpp:59:32: warning: array subscript has type ‘char’ [-Wchar-subscripts] else exista[s[nr_s]]=1; ^