题解 | #链表排序#

public ListNode sortList(ListNode head) {
if( head == null ){
return head;
}

        List<ListNode> list = new LinkedList<ListNode>();

        ListNode node = head;
        while( node!=null ){
           list.add(node);
           node = node.next;
        }


        list.sort(new Comparator<ListNode>() {

            @Override
            public int compare(ListNode o1, ListNode o2) {
                return o1.val > o2.val ? 1 : (o1.val == o2.val ? 0 : -1);
            }
        });
    head = new ListNode(0);
    ListNode r = head;
    for (ListNode n : list) {
        System.out.print(n.val + " ");
        r.next = n;
        r = n;
    }
    r.next = null;

    return head.next;
}