Leetcode 147. Insertion Sort List

public ListNode insertionSortList(ListNode head) {
if(head == null){
return null;
}
ListNode phead =head.next;
ListNode Head = new ListNode(0);//设置的伪头结点
Head.next = head;
head.next = null;
ListNode p = Head;
while(phead!= null){
p = Head;
while(p.next!= null && p.next.val < phead.val){
p = p.next;
}
ListNode temp = phead;
phead = phead.next;

temp.next = p.next;
p.next = temp;
}
return Head.next;
}