find the average of all nodes in a linked list in php

To find the average of all nodes in a linked list in PHP, we need to traverse the entire list and calculate the sum of all node values. Then, we can divide the sum by the total number of nodes in the list to get the average.

Here's a PHP function that implements this approach:

main.php
/**
 * Finds the average of all nodes in a linked list.
 *
 * @param ListNode $head The head node of the linked list.
 * @return float The average of all node values.
 */
function findLinkedListAverage(ListNode $head): float {
  $sum = 0;
  $count = 0;
  
  // Traverse the linked list and calculate sum of all node values.
  $cur = $head;
  while ($cur != null) {
    $sum += $cur->val;
    $count++;
    $cur = $cur->next;
  }
  
  return $sum / $count;
}
458 chars
21 lines

This function takes the head node of the linked list as input, and returns the average of all node values as a float.

Note that this implementation assumes that the ListNode class has a val property that stores the value of the node, and a next property that points to the next node in the list. You may need to adjust this code if your ListNode class has different property names or structures.