LeetCode:328. 奇偶链表387. 字符串中的第一个唯一字符（python3）

Posted 2021-06-15 南岸青栀*

328. 奇偶链表

# Definition for singly-linked list.
# class ListNode:
#     def __init__(self, val=0, next=None):
#         self.val = val
#         self.next = next
class Solution:
    def oddEvenList(self, head: ListNode) -> ListNode:
        if head == None: return head
        evenHead = head.next
        odd,even = head,evenHead
        while even and even.next:
            odd.next = even.next
            odd = odd.next
            even.next = odd.next
            even = even.next
        odd.next = evenHead
        return head

387. 字符串中的第一个唯一字符

法1：第一次出现记录索引，第二次出现将其设置为字符串长度+1；遍历之后查看最小值是否大于字符串长度，最小值不大于字符串长度即为唯一字符的索引。

class Solution:
    def firstUniqChar(self, s: str) -> int:
        dic = {}
        for i in range(len(s)):
            if s[i] not in dic:
                dic[s[i]] = i
            else:
                dic[s[i]] = len(s)+1
        res = min(dic.values())
        return -1 if res>len(s) else res