Refactor dlistint_len function for improved performance and clarity

Renamed variables for better readability and consistency
Replaced while loop with a for loop for iterating through the list
Removed unnecessary assignment and improved code structure
Updated function documentation and comments

Author: nwhator

0x17-doubly_linked_lists/1-dlistint_len.c

@@ -0,0 +1,23 @@
+#include "lists.h"
+
+/**
+ * dlistint_len - Returns the number of elements in a linked dlistint_t list.
+ * @h: Pointer to head of the list.
+ *
+ * Return: The number of elements in the list.
+ */
+
+size_t dlistint_len(const dlistint_t *h)
+{
+	size_t count = 0;
+
+	/* Iterate through the list until reaching the end */
+	while (h)
+	{
+		/* Increment the count for each node encountered */
+		count++;
+		/* Move to the next node */
+		h = h->next;
+	}
+	return (count);
+}

0x17-doubly_linked_lists/1-main.c

@@ -0,0 +1,34 @@
+#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;
+    dlistint_t *new;
+    dlistint_t hello = {8, NULL, NULL};
+    size_t n;
+
+    head = &hello;
+    new = malloc(sizeof(dlistint_t));
+    if (new == NULL)
+    {
+        dprintf(2, "Error: Can't malloc\n");
+        return (EXIT_FAILURE);
+    }
+    new->n = 9;
+    head->prev = new;
+    new->next = head;
+    new->prev = NULL;
+    head = new;
+    n = dlistint_len(head);
+    printf("-> %lu elements\n", n);
+    free(new);
+    return (EXIT_SUCCESS);
+}