题目浅析

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  • 简单地说，就是给一个链表和一个数组，链表中的每个节点都是唯一值的整数，数组中有链表的子集，求链表中连续的在数组中的节点块数（组件数）。

思路分享

代码解答（强烈建议自行解答后再看）

  • 参考题解
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# Definition for singly-linked list.
# class ListNode:
#     def __init__(self, val=0, next=None):
#         self.val = val
#         self.next = next
class Solution:
    def numComponents(self, head: Optional[ListNode], nums: List[int]) -> int:
        # 用标志位
        flag = False
        ans = 0
        rec = Counter(nums)
        while head:
            if rec[head.val] > 0:
                flag = True
            elif flag:
                flag = False
                ans += 1
            head = head.next
        return ans + (1 if flag else 0)

        # 第一版答案
        # first, last = head, head
        # com_num = 0
        # rec = Counter(nums)
        # while first and last:
        #     while first and rec[first.val] == 0:
        #         first = first.next

        #     if first:
        #         com_num += 1
        #         last = first
        #         while last and rec[last.val] > 0:
        #             last = last.next
            
        #     if last:
        #         last = last.next
        #     first = last

        # return com_num