sfds

list.c

@@ -1,11 +1,9 @@
-
 #include <assert.h>
 #include <string.h>
 
 #include "util.h"
 #include "list.h"
 
-
 void
 list_init(list *l)
 {
@@ -26,21 +24,48 @@ void
 list_clear(list *l, list_free_cb cb)
 {
 	assert(l);
-	// <YOURCODE>
+	list_node *current = l->head;
+	while (current != NULL) {
+		list_node *next = current->next;
+		if (cb != NULL) {
+			cb(current);
+		}
+		current = next;
+	}
+	l->head = NULL;
+	l->tail = NULL;
 }
 
 void
 list_push_front(list *l, list_node *item)
 {
 	assert(l && item);
-	// <YOURCODE>
+	list_node_orphan(item);
+	
+	if (l->head == NULL) {
+		l->head = item;
+		l->tail = item;
+	} else {
+		item->next = l->head;
+		l->head->prev = item;
+		l->head = item;
+	}
 }
 
 void
 list_push_back(list *l, list_node *item)
 {
 	assert(l && item);
-	// <YOURCODE>
+	list_node_orphan(item);
+	
+	if (l->tail == NULL) {
+		l->head = item;
+		l->tail = item;
+	} else {
+		item->prev = l->tail;
+		l->tail->next = item;
+		l->tail = item;
+	}
 }
 
 list_node *
@@ -61,39 +86,82 @@ size_t
 list_len(list *l)
 {
 	assert(l);
-	// <YOURCODE>
-	return 0;
+	size_t count = 0;
+	list_node *current = l->head;
+	while (current != NULL) {
+		count++;
+		current = current->next;
+	}
+	return count;
 }
 
 list_node *
 list_get(list *l, int idx)
 {
 	assert(l);
-	// <YOURCODE>
-	return NULL;
+	if (idx < 0) return NULL;
+	
+	list_node *current = l->head;
+	int i = 0;
+	while (current != NULL && i < idx) {
+		current = current->next;
+		i++;
+	}
+	return current;
 }
 
 void
 list_insert(list *l, list_node *item, int idx)
 {
 	assert(l && item);
-	// <YOURCODE>
+	
+	if (idx <= 0) {
+		list_push_front(l, item);
+		return;
+	}
+	
+	list_node *current = list_get(l, idx);
+	if (current == NULL) {
+		list_push_back(l, item);
+	} else {
+		list_node_orphan(item);
+		item->prev = current->prev;
+		item->next = current;
+		current->prev->next = item;
+		current->prev = item;
+	}
 }
 
 list_node *
 list_pop_front(list *l)
 {
 	assert(l);
-	// <YOURCODE>
-	return NULL;
+	if (l->head == NULL) return NULL;
+	
+	list_node *node = l->head;
+	l->head = node->next;
+	if (l->head != NULL) {
+		l->head->prev = NULL;
+	} else {
+		l->tail = NULL;
+	}
+	return list_node_orphan(node);
 }
 
 list_node *
 list_pop_back(list *l)
 {
 	assert(l);
-	// <YOURCODE>
-	return NULL;
+	if (l->tail == NULL) return NULL;
+	
+	list_node *node = l->tail;
+	l->tail = node->prev;
+	if (l->tail != NULL) {
+		l->tail->next = NULL;
+	} else {
+		l->head = NULL;
+	}
+	return list_node_orphan(node);
 }
 
 int
@@ -114,18 +182,49 @@ list_node *
 list_remove(list *l, int idx)
 {
 	assert(l);
-	// <YOURCODE>
-	return NULL;
+	if (idx < 0) return NULL;
+	
+	if (idx == 0) {
+		return list_pop_front(l);
+	}
+	
+	list_node *node = list_get(l, idx);
+	if (node == NULL) return NULL;
+	
+	if (node->next != NULL) {
+		node->next->prev = node->prev;
+	}
+	if (node->prev != NULL) {
+		node->prev->next = node->next;
+	}
+	
+	if (node == l->tail) {
+		l->tail = node->prev;
+	}
+	
+	return list_node_orphan(node);
 }
 
 void
 list_reverse(list *l)
 {
 	assert(l);
-	// <YOURCODE>
+	list_node *current = l->head;
+	list_node *temp = NULL;
+	
+	while (current != NULL) {
+		temp = current->prev;
+		current->prev = current->next;
+		current->next = temp;
+		current = current->prev;
+	}
+	
+	if (temp != NULL) {
+		l->tail = l->head;
+		l->head = temp->prev;
+	}
 }
 
-
 void
 list_pass(list *l, list_pass_cb cb, void *opaq)
 {
@@ -133,4 +232,4 @@ list_pass(list *l, list_pass_cb cb, void *opaq)
 	list_for_each(iter, l) {
 		cb(iter, opaq);
 	}
-}
+}