#include <stdio.h>
 
struct node {int elem;struct node *next;};
typedef struct node *list;

list midcell(list L) {
	list m;
	for (m = L; L && L->next; L = L->next->next) m = m->next;
	return m;
}

list revfR_sub(list L, list M, list N) {
	if (L == M) return N;
	list r = revfR_sub(L->next, M, L);
	L->next = N;
	return r;
}

list revfR(list L, list M) {
	return revfR_sub(L, M, NULL);
}

list revf(list L, list M) {
	list p, n;
	for (p = NULL; L != M;) {
		n = L->next;
		L->next = p;
		p = L;
		L = n;
	}
	return p;
}

struct node nodes[10];

list init() {
	int i;
	for (i = 0; i < 10; ++i) nodes[i].elem = i;
	for (i = 0; i < 9; ++i) nodes[i].next = &nodes[i+1];
	nodes[9].next = NULL;
	return &nodes[0];
}

void print(char* s, list p) {
	printf("%s: ", s);
	for (; p; p = p->next) printf("%d ", p->elem);
	printf("\n");
}

int main () {
	list m;
	print("init    ", init());
	print("midcell ", m = midcell(init()));
	print("revfR   ", revfR(init(), m));
	print("revfR(M)", m);
	print("revf    ", revf(init(), m));
	print("revf(M) ", m);
	return 0;
}