添加 0019.删除链表的倒数第N个节点 python3版本

Author: morningsky

problems/0019.删除链表的倒数第N个节点.md

@@ -112,6 +112,30 @@ class Solution {
     }
 }
 ```
+
+Python:
+```python
+# Definition for singly-linked list.
+# class ListNode:
+#     def __init__(self, val=0, next=None):
+#         self.val = val
+#         self.next = next
+class Solution:
+    def removeNthFromEnd(self, head: ListNode, n: int) -> ListNode:
+        head_dummy = ListNode()
+        head_dummy.next = head
+
+        slow, fast = head_dummy, head_dummy
+        while(n!=0): #fast先往前走n步
+            fast = fast.next
+            n -= 1
+        while(fast.next!=None):
+            slow = slow.next
+            fast = fast.next
+        #fast 走到结尾后，slow的下一个节点为倒数第N个节点
+        slow.next = slow.next.next #删除
+        return head_dummy.next
+```
 Go:
 ```Go
 /**