doubly list done

Author: harris-ahmad

c/LinkedList/doubly/list.c

@@ -1,32 +1,259 @@
 #include <stdio.h>
 #include <stdlib.h>
 
-// Node structure
 typedef struct Node {
-    int data;
-    struct Node* next;
-    struct Node* prev;
+    void *data;
+    struct Node *next;
+    struct Node *prev;
+    int ref_count;
 } Node;
 
-// Doubly Linked List structure
 typedef struct DoublyLinkedList {
-    Node* head;
-    Node* tail;
+    Node *head;
+    Node *tail;
 } DoublyLinkedList;
 
-// Function to create a new node
-Node* createNode(int data) {
-    Node* newNode = (Node*)malloc(sizeof(Node));
+void incrementRefCount(Node *node) {
+    if (node) {
+        node->ref_count++;
+    }
+}
+
+void decrementRefCount(Node *node) {
+    if (node) {
+        node->ref_count--;
+        if (node->ref_count <= 0) {
+            free(node);
+        }
+    }
+}
+
+Node *createNode(void *data) {
+    Node *newNode = (Node *)malloc(sizeof(Node));
     newNode->data = data;
     newNode->next = NULL;
     newNode->prev = NULL;
+    newNode->ref_count = 1;
     return newNode;
 }
 
-// Function to initialize an empty list
-DoublyLinkedList* createList() {
-    DoublyLinkedList* list = (DoublyLinkedList*)malloc(sizeof(DoublyLinkedList));
+DoublyLinkedList *createDoublyLinkedList() {
+    DoublyLinkedList *list = (DoublyLinkedList *)malloc(sizeof(DoublyLinkedList));
     list->head = NULL;
     list->tail = NULL;
     return list;
-}
+}
+
+Node *getHead(DoublyLinkedList *list) {
+    return list->head;
+}
+
+Node *getTail(DoublyLinkedList *list) {
+    return list->tail;
+}
+
+void prepend(DoublyLinkedList *list, void *data) {
+    Node *newNode = createNode(data);
+    if (!list->head) {
+        list->head = newNode;
+        list->tail = newNode;
+    } else {
+        newNode->next = list->head;
+        list->head->prev = newNode;
+        list->head = newNode;
+    }
+}
+
+void append(DoublyLinkedList *list, void *data) {
+    Node *newNode = createNode(data);
+    if (!list->head) {
+        list->head = newNode;
+        list->tail = newNode;
+    } else {
+        newNode->prev = list->tail;
+        list->tail->next = newNode;
+        list->tail = newNode;
+    }
+}
+
+void insertBetween(DoublyLinkedList *list, void *data, void *after) {
+    Node *newNode = createNode(data);
+    Node *curr = list->head;
+
+    while (curr && curr->data != after) {
+        curr = curr->next;
+    }
+
+    if (curr) {
+        newNode->next = curr->next;
+        newNode->prev = curr;
+        if (curr->next) {
+            curr->next->prev = newNode;
+        } else {
+            list->tail = newNode;
+        }
+        curr->next = newNode;
+    }
+}
+
+void deleteHead(DoublyLinkedList *list) {
+    if (list->head) {
+        Node *temp = list->head;
+        list->head = list->head->next;
+        if (list->head) {
+            list->head->prev = NULL;
+        } else {
+            list->tail = NULL;
+        }
+        decrementRefCount(temp);
+    }
+}
+
+void deleteTail(DoublyLinkedList *list) {
+    if (!list->tail) {
+        return;
+    }
+    if (list->tail == list->head) {
+        decrementRefCount(list->tail);
+        list->head = NULL;
+        list->tail = NULL;
+    } else {
+        Node *temp = list->tail;
+        list->tail = list->tail->prev;
+        list->tail->next = NULL;
+        decrementRefCount(temp);
+    }
+}
+
+void deleteAny(DoublyLinkedList *list, void *target) {
+    Node *curr = list->head;
+
+    while (curr && curr->data != target) {
+        curr = curr->next;
+    }
+
+    if (curr) {
+        if (curr->prev) {
+            curr->prev->next = curr->next;
+        } else {
+            list->head = curr->next;
+        }
+
+        if (curr->next) {
+            curr->next->prev = curr->prev;
+        } else {
+            list->tail = curr->prev;
+        }
+
+        decrementRefCount(curr);
+    }
+}
+
+int size(DoublyLinkedList *list) {
+    int count = 0;
+    Node *curr = list->head;
+    while (curr) {
+        count++;
+        curr = curr->next;
+    }
+    return count;
+}
+
+void reverseList(DoublyLinkedList *list) {
+    Node *curr = list->head;
+    Node *temp = NULL;
+
+    while (curr) {
+        temp = curr->prev;
+        curr->prev = curr->next;
+        curr->next = temp;
+        curr = curr->prev;
+    }
+
+    if (temp) {
+        list->head = temp->prev;
+    }
+}
+
+Node *find(DoublyLinkedList *list, void *data) {
+    Node *curr = list->head;
+    while (curr) {
+        if (curr->data == data) {
+            return curr;
+        }
+        curr = curr->next;
+    }
+    return NULL;
+}
+
+void clear(DoublyLinkedList *list) {
+    Node *curr = list->head;
+    Node *next;
+    while (curr) {
+        next = curr->next;
+        decrementRefCount(curr);
+        curr = next;
+    }
+    list->head = NULL;
+    list->tail = NULL;
+}
+
+void printListForward(DoublyLinkedList *list) {
+    Node *curr = list->head;
+    while (curr) {
+        printf("%p ", curr->data);
+        curr = curr->next;
+    }
+    printf("\n");
+}
+
+void printListBackward(DoublyLinkedList *list) {
+    Node *curr = list->tail;
+    while (curr) {
+        printf("%p ", curr->data);
+        curr = curr->prev;
+    }
+    printf("\n");
+}
+
+int main() {
+    DoublyLinkedList *list = createDoublyLinkedList();
+
+    int a = 1, b = 2, c = 3, d = 4;
+    append(list, &a);
+    append(list, &b);
+    prepend(list, &c);
+    insertBetween(list, &d, &a);
+
+    printf("List printed forward: ");
+    printListForward(list);
+
+    printf("List printed backward: ");
+    printListBackward(list);
+
+    deleteHead(list);
+    printf("List after deleting head: ");
+    printListForward(list);
+
+    deleteTail(list);
+    printf("List after deleting tail: ");
+    printListForward(list);
+
+    deleteAny(list, &b);
+    printf("List after deleting element b: ");
+    printListForward(list);
+
+    printf("List size: %d\n", size(list));
+
+    reverseList(list);
+    printf("List after reversing: ");
+    printListForward(list);
+
+    clear(list);
+    printf("List after clearing: ");
+    printListForward(list);
+
+    free(list);
+
+    return 0;
+}