JavaScript Tutorial ✦

Check if a Linked List is Palindrome

Function to determine if a linked list reads the same forwards and backwards.

function isPalindrome(head) {
  let fast = head, slow = head, stack = [];
  while (fast && fast.next) {
    stack.push(slow.value);
    slow = slow.next;
    fast = fast.next.next;
  }
  if (fast) slow = slow.next;
  while (slow) {
    if (slow.value !== stack.pop()) return false;
    slow = slow.next;
  }
  return true;
}