Create 0707-design-linked-list.c

c/0707-design-linked-list.c

@@ -0,0 +1,130 @@
+typedef struct Node {
+ struct Node* next;
+ struct Node* prev;
+ int val;
+} Node;
+
+typedef struct {
+ Node* head;
+ Node* tail;
+ int length;
+} MyLinkedList;
+
+Node* createNode(int val) {
+ Node* new_node = (Node*)malloc(sizeof(Node) );
+ new_node->next = NULL;
+ new_node->prev = NULL;
+ new_node->val = val;
+ return new_node;
+}
+
+MyLinkedList* myLinkedListCreate() {
+ MyLinkedList* list = (MyLinkedList*)malloc(sizeof(MyLinkedList) );
+ list->head = createNode(-1);
+ list->tail = list->head;
+ list->length = 0;
+ return list;
+}
+
+Node* traverseList(MyLinkedList* obj, int index) {
+ if (index < 0 || index >= obj->length)
+ return NULL;
+ Node* trev = obj->head;
+ while (index >= 0) {
+ trev = trev->next;
+ index -= 1;
+ }
+ return trev; 
+}
+
+int myLinkedListGet(MyLinkedList* obj, int index) {
+ Node *node = traverseList(obj, index);
+ if (node != NULL)
+ return node->val;
+ return -1;
+}
+
+void myLinkedListAddAtHead(MyLinkedList* obj, int val) {
+ Node* new_node = createNode(val);
+ new_node->next = obj->head->next;
+ new_node->prev = obj->head;
+ obj->head->next = new_node;
+ if (new_node->next != NULL)
+ new_node->next->prev = new_node;
+ else
+ obj->tail = new_node;
+ obj->length += 1;
+ return;
+}
+
+void myLinkedListAddAtTail(MyLinkedList* obj, int val) {
+ Node* new_node = createNode(val);
+ obj->tail->next = new_node;
+ new_node->prev = obj->tail;
+ obj->tail = obj->tail->next;
+ obj->length += 1;
+ return;
+}
+
+void myLinkedListAddAtIndex(MyLinkedList* obj, int index, int val) {
+ if (index == 0) {
+ myLinkedListAddAtHead(obj, val);
+ return;
+ }
+ else if (index == obj->length) {
+ myLinkedListAddAtTail(obj, val);
+ return;
+ }
+ Node* prev_node = traverseList(obj, index - 1);
+ if (prev_node == NULL)
+ return;
+ Node* new_node = createNode(val);
+ new_node->next = prev_node->next;
+ new_node->prev = prev_node;
+ prev_node->next = new_node;
+ if (new_node->next != NULL)
+ new_node->next->prev = new_node;
+ obj->length += 1;
+ return;
+}
+
+void myLinkedListDeleteAtIndex(MyLinkedList* obj, int index) {
+ Node *node = traverseList(obj, index);
+ if (node == NULL)
+ return;
+ Node *temp = node;
+ node->prev->next = node->next;
+ if (node->next != NULL)
+ node->next->prev = node->prev;
+ else
+ obj->tail = node->prev; 
+ obj->length -= 1;
+ free(temp);
+ return;
+}
+
+void myLinkedListFree(MyLinkedList* obj) {
+ Node *prev = NULL, *cur = obj->head;
+ while (cur != NULL) {
+ prev = cur;
+ cur = cur->next;
+ free(prev);
+ }
+ free(obj);
+}
+
+/**
+ * Your MyLinkedList struct will be instantiated and called as such:
+ * MyLinkedList* obj = myLinkedListCreate();
+ * int param_1 = myLinkedListGet(obj, index);
+ 
+ * myLinkedListAddAtHead(obj, val);
+ 
+ * myLinkedListAddAtTail(obj, val);
+ 
+ * myLinkedListAddAtIndex(obj, index, val);
+ 
+ * myLinkedListDeleteAtIndex(obj, index);
+ 
+ * myLinkedListFree(obj);
+*/