2277. Closest Node to Path in Tree
Description
You are given a positive integer n
representing the number of nodes in a tree, numbered from 0
to n - 1
(inclusive). You are also given a 2D integer array edges
of length n - 1
, where edges[i] = [node1i, node2i]
denotes that there is a bidirectional edge connecting node1i
and node2i
in the tree.
You are given a 0-indexed integer array query
of length m
where query[i] = [starti, endi, nodei]
means that for the ith
query, you are tasked with finding the node on the path from starti
to endi
that is closest to nodei
.
Return an integer array answer
of length m
, where answer[i]
is the answer to the ith
query.
Example 1:
![](https://spcdn.pages.dev/leetcode/problems/2277.Closest%20Node%20to%20Path%20in%20Tree/images/image-20220514132158-1.png)
Input: n = 7, edges = [[0,1],[0,2],[0,3],[1,4],[2,5],[2,6]], query = [[5,3,4],[5,3,6]] Output: [0,2] Explanation: The path from node 5 to node 3 consists of the nodes 5, 2, 0, and 3. The distance between node 4 and node 0 is 2. Node 0 is the node on the path closest to node 4, so the answer to the first query is 0. The distance between node 6 and node 2 is 1. Node 2 is the node on the path closest to node 6, so the answer to the second query is 2.
Example 2:
![](https://spcdn.pages.dev/leetcode/problems/2277.Closest%20Node%20to%20Path%20in%20Tree/images/image-20220514132318-2.png)
Input: n = 3, edges = [[0,1],[1,2]], query = [[0,1,2]] Output: [1] Explanation: The path from node 0 to node 1 consists of the nodes 0, 1. The distance between node 2 and node 1 is 1. Node 1 is the node on the path closest to node 2, so the answer to the first query is 1.
Example 3:
![](https://spcdn.pages.dev/leetcode/problems/2277.Closest%20Node%20to%20Path%20in%20Tree/images/image-20220514132333-3.png)
Input: n = 3, edges = [[0,1],[1,2]], query = [[0,0,0]] Output: [0] Explanation: The path from node 0 to node 0 consists of the node 0. Since 0 is the only node on the path, the answer to the first query is 0.
Constraints:
1 <= n <= 1000
edges.length == n - 1
edges[i].length == 2
0 <= node1i, node2i <= n - 1
node1i != node2i
1 <= query.length <= 1000
query[i].length == 3
0 <= starti, endi, nodei <= n - 1
- The graph is a tree.