Insertion sort

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int x) {
 *         val = x;
 *         next = null;
 *     }
 * }
 */
public class Solution {
    public ListNode insertionSortList(ListNode head) {
        if (head == null) {
            return null;
        }
        ListNode newHead = new ListNode(head.val);

        ListNode oldCurrent = head.next;

        while (oldCurrent != null) {

            ListNode newNode = new ListNode(oldCurrent.val);
            if (newNode.val <= newHead.val) {
                newNode.next = newHead;
                newHead = newNode;
            } else {
                ListNode newCurrent = newHead;
                while (newCurrent != null) {

                    if (newCurrent.next == null || newNode.val <= newCurrent.next.val) {
                        newNode.next = newCurrent.next;
                        newCurrent.next = newNode;
                        break;
                    }
                    newCurrent = newCurrent.next;
                }
            }

            oldCurrent = oldCurrent.next;
        }
        return newHead;
    }
}