🐱(link): 147. 对链表进行插入排序

Author: JalanJiang

docs/data-structure/linked_list/README.md

@@ -475,6 +475,52 @@ class Solution:
  return False
 ```
 
+## 147. 对链表进行插入排序
+
+[原题链接](https://leetcode-cn.com/problems/insertion-sort-list/)
+
+### Tail 优化版
+
+```python
+# Definition for singly-linked list.
+# class ListNode:
+# def __init__(self, x):
+# self.val = x
+# self.next = None
+
+class Solution:
+ def insertionSortList(self, head: ListNode) -> ListNode:
+ if head is None or head.next is None:
+ return head
+
+ # 固定头部
+ new_head = ListNode(float("-inf"))
+
+ cur = head
+ pre = new_head
+
+ # 加入尾部
+ tail = new_head
+
+ while cur is not None:
+ if tail.val < cur.val:
+ tail.next = cur
+ tail = cur
+ cur = cur.next
+ else:
+ cur_next = cur.next
+ # 此时：tail.next = cur，会产生循环，故断开
+ tail.next = cur_next
+ while pre.next is not None and pre.next.val < cur.val:
+ pre = pre.next
+ cur.next = pre.next
+ pre.next = cur
+ cur = cur_next
+ pre = new_head
+
+ return new_head.next
+```
+
 ## 148. 排序链表
 
 [原题链接](https://leetcode-cn.com/problems/sort-list/)