LeetCode-LinkedList1

Title:

T83.Remove Duplicates from Sorted List

Related Topics:

LinkedList

Describe:

Given a sorted linked list, delete all duplicates such that each element appear only once.

Sample Input&output:

1. Input: 1->1->2
   Output: 1->2
2. Input: 1->1->2->3->3
   Output: 1->2->3

Code:

# 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
        """
        if head:
            val_list = []
            val_list.append(head.val)
            first = ListNode(head.val-1)
            first.next = head
            while head and head.next:
                tmp = head.next
                if tmp.val in val_list:
                    head.next = tmp.next
                    tmp = head.next
                else:
                    val_list.append(head.next.val)
                    head = tmp
            return first.next

Record:

1. 循環遍歷列表時，要注意while循環的條件，如果已經到了末尾，一個NoneType是沒有next的，會報錯。
2. https://blog.csdn.net/Lynette_bb/article/details/73414134 有另一種方法，而這裏是通過儲存值的列表來確保無重複。