Compilare: user.cpp: In function ‘void variabile(char*, int*)’: user.cpp:14:23: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (v[s[i]] == 0) ^ user.cpp: In function ‘int main()’: user.cpp:52:12: warning: unused variable ‘nrv1’ [-Wunused-variable] int n, nrv1, nrv2, i, j, k; ^ user.cpp:52:18: warning: unused variable ‘nrv2’ [-Wunused-variable] int n, nrv1, nrv2, i, j, k; ^