Compilare: user.c: In function ‘rem’: user.c:78:5: warning: implicit declaration of function ‘malloc’ [-Wimplicit-function-declaration] node* n = malloc(sizeof(node)); ^ user.c:78:15: warning: incompatible implicit declaration of built-in function ‘malloc’ [enabled by default] node* n = malloc(sizeof(node)); ^ user.c: In function ‘paste’: user.c:88:17: warning: incompatible implicit declaration of built-in function ‘malloc’ [enabled by default] node* mix = malloc(sizeof(node)); ^ user.c: In function ‘print’: user.c:100:9: warning: format ‘%d’ expects argument of type ‘int’, but argument 2 has type ‘ulong’ [-Wformat=] printf("%d", h->nodes[i].value); ^ user.c: In function ‘main’: user.c:146:32: warning: incompatible implicit declaration of built-in function ‘malloc’ [enabled by default] huffman *huff = (huffman*) malloc((n+1) * sizeof(huffman)); ^