Compilare: user.cpp: In function ‘void multiply(int (*)[3], int (*)[3], int (*)[3])’: user.cpp:13:21: warning: argument to ‘sizeof’ in ‘void* memset(void*, int, size_t)’ call is the same expression as the destination; did you mean to dereference it? [-Wsizeof-pointer-memaccess] memset(C, 0, sizeof(C)); ^