Compilare: user.cpp: In function ‘void fre(long long int)’: user.cpp:37:14: warning: array subscript has type ‘char’ [-Wchar-subscripts] rz=rz+f[ch]; ^ user.cpp:42:14: warning: array subscript has type ‘char’ [-Wchar-subscripts] rz=rz+f[ch]*(dr/4)+fc[ch]*(dr/4); ^ user.cpp:42:28: warning: array subscript has type ‘char’ [-Wchar-subscripts] rz=rz+f[ch]*(dr/4)+fc[ch]*(dr/4); ^ user.cpp:47:14: warning: array subscript has type ‘char’ [-Wchar-subscripts] rz=rz+f[ch]*(dr/4)+fc[ch]*(dr/4*2); ^ user.cpp:47:28: warning: array subscript has type ‘char’ [-Wchar-subscripts] rz=rz+f[ch]*(dr/4)+fc[ch]*(dr/4*2); ^ user.cpp: In function ‘int main()’: user.cpp:63:9: warning: array subscript has type ‘char’ [-Wchar-subscripts] f[s[i]]++; ^ user.cpp:64:15: warning: array subscript has type ‘char’ [-Wchar-subscripts] s1[i]=f[s[i]]; ^