having a tech seminar with Naofu

24-swap-nodes-in-pairs.py

@@ -0,0 +1,25 @@
+# Definition for singly-linked list.
+# class ListNode(object):
+#     def __init__(self, x):
+#         self.val = x
+#         self.next = None
+
+class Solution(object):
+    def swapPairs(self, head):
+        """
+        :type head: ListNode
+        :rtype: ListNode
+        """
+        dummy = ListNode(0)
+        dummy.next = head
+        ret = dummy
+        while dummy.next and dummy.next.next:
+            curr = dummy.next
+            after = curr.next
+            temp = after.next
+            dummy.next = after
+            after.next = curr
+            curr.next = temp
+
+            dummy = dummy.next.next
+        return ret.next

83-remove-duplicateds-from-sorted-list

@@ -0,0 +1,19 @@
+# Definition for singly-linked list.
+# class ListNode(object):
+#     def __init__(self, x):
+#         self.val = x
+#         self.next = None
+
+class Solution(object):
+    def deleteDuplicates(self, head):
+        """
+        :type head: ListNode
+        :rtype: ListNode
+        """
+        ret = head
+        while head and head.next:
+            if head.next.val == head.val:
+                head.next = head.next.next
+            else:
+                head = head.next
+        return ret