Compilare: user.c: In function ‘main’: user.c:22:5: warning: implicit declaration of function ‘malloc’ [-Wimplicit-function-declaration] int *STK = malloc(MAX * sizeof(int)), ^ user.c:22:16: warning: incompatible implicit declaration of built-in function ‘malloc’ [enabled by default] int *STK = malloc(MAX * sizeof(int)), ^ user.c:24:9: warning: unused variable ‘v’ [-Wunused-variable] int v, i, f = 0, b = 0; ^