Deletion in linked list

deletion_in_linked_list.cpp

@@ -0,0 +1,113 @@
+#include<stdio.h>
+#include<stdlib.h>
+
+struct Node
+{
+    int data;
+    struct Node * next;
+};
+
+void linkedListTraversal(struct Node *ptr)
+{
+    while(ptr != NULL){
+        printf("Element: %d\n", ptr->data);
+        ptr = ptr->next;
+    }
+}
+
+//------------------------------------------------------------------------------------------
+
+struct Node * deleteFirst(struct Node * head){
+    struct Node * ptr = head;
+    head = head->next;
+    free(ptr);
+    return head;
+}
+
+struct Node * deleteAtIndex(struct Node * head, int index){
+    struct Node * p = head;
+    struct Node * q = head->next;
+
+    for (int i = 0; i < (index-1); i++)
+    {
+        p = p->next;
+        q = q->next;
+    }
+
+    p->next = q->next;
+    free(q);
+    return head;
+}
+
+struct Node * deleteAtEnd(struct Node * head){
+    struct Node * p = head;
+    struct Node * q = head->next;
+
+    while(q->next != NULL)
+    {
+        p = p->next;
+        q = q->next;
+    }
+
+    p->next = NULL;
+    free(q);
+    return head;
+}
+
+struct Node * deleteAtValue(struct Node * head, int value){
+    struct Node * p = head;
+    struct Node * q = head->next;
+
+    while(q->data != value && q->next != NULL)
+    {
+        p = p->next;
+        q = q->next;
+    }
+
+    if (q->data == value)
+    {
+        p->next = q->next;
+        free(q);
+    }
+    return head;
+}
+
+int main(){
+    struct Node *head;
+    struct Node *second;
+    struct Node *third;
+    struct Node *fourth;
+
+    // Allocate memory for nodes in the linkedlist.
+    head = (struct Node*)malloc(sizeof(struct Node));
+    second = (struct Node*)malloc(sizeof(struct Node));
+    third = (struct Node*)malloc(sizeof(struct Node));
+    fourth = (struct Node*)malloc(sizeof(struct Node));
+
+    // Link first and second nodes
+    head->data = 4;
+    head->next = second;
+
+    // Link second and third nodes
+    second->data = 3;
+    second->next = third;
+
+    // Link third and fourth nodes
+    third->data = 8;
+    third->next = fourth;
+
+    // Terminate the list at the third node
+    fourth->data = 1;
+    fourth->next = NULL;
+
+    printf("Linked List before traversal\n");
+    linkedListTraversal(head);
+
+    printf("Linked List after traversal\n");
+    // head = deleteFirst(head);
+    // head = deleteAtIndex(head, 2);
+    // head = deleteAtEnd(head);
+    head = deleteAtValue(head, 3);
+    linkedListTraversal(head);
+    return 0;
+}