Insertion Sort List

Sort a linked list using insertion sort.

Solution:

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int x) { val = x; }
 * }
 */
public class Solution {
  public ListNode insertionSortList(ListNode head) {
    ListNode curr = head, next = null;
    ListNode l = new ListNode(0);
    while (curr != null) {
      next = curr.next;
      ListNode p = l;
      while (p.next != null && p.next.val < curr.val) {
          p = p.next;
      }
      curr.next = p.next;
      p.next = curr;
      curr = next;
    }
    return l.next;
  }
}