插入排序
注意维护,三个指针:next,prev,cur
/**
* 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) {
if (head == null || head.next == null) {
return head;
}
ListNode sortedNode = new ListNode(0);
ListNode cur = head;
while (cur != null) {
ListNode next = cur.next;
ListNode prev = sortedNode;
while (prev.next != null && prev.next.val <= cur.val) {
prev = prev.next;
}
cur.next = prev.next;
prev.next = cur;
cur = next;
}
return sortedNode.next;
}
}