Compilare: user.c: In function 'mul': user.c:31: warning: implicit declaration of function 'memset' user.c:31: warning: incompatible implicit declaration of built-in function 'memset' user.c:38: warning: implicit declaration of function 'memcpy' user.c:38: warning: incompatible implicit declaration of built-in function 'memcpy' user.c: In function 'main': user.c:69: warning: format '%d' expects type 'int *', but argument 3 has type 'long int *' user.c:69: warning: format '%d' expects type 'int *', but argument 4 has type 'long int *'