Compilare: user.cpp:139:3: warning: no newline at end of file user.cpp: In function 'char* tran(int)': user.cpp:56: warning: address of local variable 'x' returned user.cpp:56: warning: unused variable 'y' user.cpp: In function 'char* dif(char*, char*)': user.cpp:91: warning: array subscript has type 'char' user.cpp:91: warning: array subscript has type 'char' user.cpp:71: warning: address of local variable 'c' returned user.cpp: In function 'char* prod(char*, char*)': user.cpp:99: warning: address of local variable 'p' returned user.cpp:98: warning: unused variable 'x'