单链表反转非递归

static Node reverseLinkedList(Node node) {
    Node previousNode = null;
    Node currentNode = node;
    Node headNode = null;
    while (currentNode != null) {
        Node nextNode = currentNode.next;
        if (nextNode == null) {
            headNode = currentNode;
        }
        currentNode.next = previousNode;
        previousNode = currentNode;
        currentNode = nextNode;
    }
    return headNode;
}