- Difficulty: Medium
- Tags: LeetCode, Medium, Tree, Depth-First Search, Breadth-First Search, Union Find, Graph, Array, Hash Table, leetcode-2368, O(n), BFS
Problem
There is an undirected tree with n
nodes labeled from 0
to n - 1
and n - 1
edges.
You are given a 2D integer array edges
of length n - 1
where edges[i] = [ai, bi]
indicates that there is an edge between nodes ai
and bi
in the tree. You are also given an integer array restricted
which represents restricted nodes.
Return the maximum number of nodes you can reach from node 0
without visiting a restricted node.
Note that node 0
will not be a restricted node.
Example 1:
Input: n = 7, edges = [[0,1],[1,2],[3,1],[4,0],[0,5],[5,6]], restricted = [4,5] Output: 4 Explanation: The diagram above shows the tree. We have that [0,1,2,3] are the only nodes that can be reached from node 0 without visiting a restricted node.
Example 2:
Input: n = 7, edges = [[0,1],[0,2],[0,5],[0,4],[3,2],[6,5]], restricted = [4,2,1] Output: 3 Explanation: The diagram above shows the tree. We have that [0,5,6] are the only nodes that can be reached from node 0 without visiting a restricted node.
Constraints:
2 <= n <= 105
edges.length == n - 1
edges[i].length == 2
0 <= ai, bi < n
ai != bi
edges
represents a valid tree.1 <= restricted.length < n
1 <= restricted[i] < n
- All the values of
restricted
are unique.