Compilare: user.cpp: In function ‘int main()’: user.cpp:8:30: warning: array subscript has type ‘char’ [-Wchar-subscripts] for(n=0;s[n];++n) fr[s[n]]++; ^ user.cpp:11:20: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(fr[j]==(n-i)/2+1) c=j, w=0; ^ user.cpp:13:20: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(fr[j] && j!=cv) c=j, w=0; ^ user.cpp:14:19: warning: array subscript has type ‘char’ [-Wchar-subscripts] g<<c; fr[c]--; cv=c; ^