Implement delete_dnodeint_at_index function to delete the node at a given index in a doubly linked list

Traverse the list to find the node at the specified index
If the node is found:

If it is the first node, update the head pointer and the prev pointer of the next node
If it is not the first node, update the next pointer of the previous node and the prev pointer of the next node
Free the memory of the node
Return 1 to indicate successful deletion
If the node is not found (index out of range), return -1 to indicate deletion failure
Added proper documentation and comments

Author: nwhator

0x17-doubly_linked_lists/8-delete_dnodeint.c

@@ -0,0 +1,49 @@
+#include "lists.h"
+
+/**
+ * delete_dnodeint_at_index - deletes the node at a given index in linked list
+ * @head: pointer to the head of the list
+ * @index: index of the node to be deleted
+ *
+ * Return: 1 if deletion succeeded, -1 if it failed
+ */
+
+int delete_dnodeint_at_index(dlistint_t **head, unsigned int index)
+{
+	dlistint_t *head1 = *head, *head2;
+	unsigned int i;
+
+	if (head1)
+		/* Move to the first node if not already */
+		while (head1->prev)
+			head1 = head1->prev;
+	i = 0;
+	while (head1)
+	{
+		if (i == index)
+		{
+			if (i == 0)
+			{
+				/* Update head if deleting first node */
+				*head = head1->next;
+				if (*head != NULL)
+					(*head)->prev = NULL;
+			}
+			else
+			{
+				/* Update previous node's next pointer */
+				head2->next = head1->next;
+				/* Update next node's previous pointer */
+				if (head1->next != NULL)
+					head1->next->prev = head2;
+			}
+			free(head1);
+			return (1);
+		}
+		head2 = head1; /* Moves head2 to the current node */
+		head1 = head1->next; /* Moves head1 to the nest node */
+		i++;
+	}
+	/* Index out of range, deletion failed */
+	return (-1);
+}

0x17-doubly_linked_lists/8-main.c

@@ -0,0 +1,68 @@
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include "lists.h"
+
+/**
+ * main - check the code
+ *
+ * Return: Always EXIT_SUCCESS.
+ */
+int main(void)
+{
+    dlistint_t *head;
+
+    head = NULL;
+    add_dnodeint_end(&head, 0);
+    add_dnodeint_end(&head, 1);
+    add_dnodeint_end(&head, 2);
+    add_dnodeint_end(&head, 3);
+    add_dnodeint_end(&head, 4);
+    add_dnodeint_end(&head, 98);
+    add_dnodeint_end(&head, 402);
+    add_dnodeint_end(&head, 1024);
+    print_dlistint(head);
+    printf("-----------------\n");
+    delete_dnodeint_at_index(&head, 5);
+    print_dlistint(head);
+    printf("-----------------\n");
+    delete_dnodeint_at_index(&head, 0);
+    print_dlistint(head);
+    printf("-----------------\n");
+    delete_dnodeint_at_index(&head, 0);
+    print_dlistint(head);
+    printf("-----------------\n");
+    delete_dnodeint_at_index(&head, 0);
+    print_dlistint(head);
+    printf("-----------------\n");
+    delete_dnodeint_at_index(&head, 0);
+    print_dlistint(head);
+    printf("-----------------\n");
+    delete_dnodeint_at_index(&head, 0);
+    print_dlistint(head);
+    printf("-----------------\n");
+    delete_dnodeint_at_index(&head, 0);
+    print_dlistint(head);
+    printf("-----------------\n");
+    delete_dnodeint_at_index(&head, 0);
+    printf("-----------------\n");
+    delete_dnodeint_at_index(&head, 0);
+    printf("-----------------\n");
+    delete_dnodeint_at_index(&head, 0);
+    printf("-----------------\n");
+    delete_dnodeint_at_index(&head, 0);
+    printf("-----------------\n");
+    delete_dnodeint_at_index(&head, 0);
+    printf("-----------------\n");
+    delete_dnodeint_at_index(&head, 0);
+    printf("-----------------\n");
+    delete_dnodeint_at_index(&head, 0);
+    printf("-----------------\n");
+    delete_dnodeint_at_index(&head, 0);
+    printf("-----------------\n");
+    delete_dnodeint_at_index(&head, 0);
+    printf("-----------------\n");
+    delete_dnodeint_at_index(&head, 0);
+    print_dlistint(head);
+    return (0);
+}