mirror of
https://github.com/halfrost/LeetCode-Go.git
synced 2025-07-05 08:27:30 +08:00
58 lines
1.8 KiB
Markdown
58 lines
1.8 KiB
Markdown
# [817. Linked List Components](https://leetcode.com/problems/linked-list-components/)
|
||
|
||
## 题目
|
||
|
||
We are given head, the head node of a linked list containing unique integer values.
|
||
|
||
We are also given the list G, a subset of the values in the linked list.
|
||
|
||
Return the number of connected components in G, where two values are connected if they appear consecutively in the linked list.
|
||
|
||
Example 1:
|
||
|
||
```c
|
||
Input:
|
||
head: 0->1->2->3
|
||
G = [0, 1, 3]
|
||
Output: 2
|
||
Explanation:
|
||
0 and 1 are connected, so [0, 1] and [3] are the two connected components.
|
||
```
|
||
|
||
Example 2:
|
||
|
||
```c
|
||
Input:
|
||
head: 0->1->2->3->4
|
||
G = [0, 3, 1, 4]
|
||
Output: 2
|
||
Explanation:
|
||
0 and 1 are connected, 3 and 4 are connected, so [0, 1] and [3, 4] are the two connected components.
|
||
```
|
||
|
||
Note:
|
||
|
||
- If N is the length of the linked list given by head, 1 <= N <= 10000.
|
||
- The value of each node in the linked list will be in the range [0, N - 1].
|
||
- 1 <= G.length <= 10000.
|
||
- G is a subset of all values in the linked list.
|
||
|
||
|
||
|
||
## 题目大意
|
||
|
||
这道题题目的意思描述的不是很明白，我提交了几次 WA 以后才悟懂题意。
|
||
|
||
这道题的意思是，在 G 中能组成多少组子链表，这些子链表的要求是能在原链表中是有序的。
|
||
|
||
## 解题思路
|
||
|
||
这个问题再抽象一下就成为这样：在原链表中去掉 G 中不存在的数，会被切断成几段链表。例如，将原链表中 G 中存在的数标为 0，不存在的数标为 1 。原链表标识为 0-0-0-1-0-1-1-0-0-1-0-1，那么这样原链表被断成了 4 段。只要在链表中找 0-1 组合就可以认为是一段，因为这里必定会有一段生成。
|
||
|
||
考虑末尾的情况，0-1，1-0，0-0，1-1，这 4 种情况的特征都是，末尾一位只要是 0，都会新产生一段。所以链表末尾再单独判断一次，是 0 就再加一。
|
||
|
||
|
||
|
||
|
||
|