Compilare: user.cpp: In function ‘void eval(char, char)’: user.cpp:24:26: warning: array subscript has type ‘char’ [-Wchar-subscripts] freq[s[point]] += ( power * localpower ); ^ user.cpp:25:31: warning: array subscript has type ‘char’ [-Wchar-subscripts] if ( !vis[s[point]] ) ^ user.cpp:26:29: warning: array subscript has type ‘char’ [-Wchar-subscripts] vis[s[point]] = 1; ^ user.cpp: In function ‘int main()’: user.cpp:53:20: warning: array subscript has type ‘char’ [-Wchar-subscripts] if ( !vis[i] ) ^ user.cpp:56:33: warning: array subscript has type ‘char’ [-Wchar-subscripts] f2 << i << ' ' << freq[i] << '\n'; ^