Insertion Sort List

Sort a linked list using insertion sort.

public class Solution {

    //Time: O(n^2)
    public ListNode insertionSortList(ListNode head) {
        if (head == null || head.next == null) {
            return head;
        }
        
        ListNode dummy = new ListNode(0);
        while (head != null) {
            ListNode node = dummy;
            while (node.next != null && node.next.val < head.val) {
                node = node.next;
            }
            
            ListNode temp = head.next;
            head.next = node.next;
            node.next = head;
            head = temp;
        }
        return dummy.next;
    }
}