1361. Validate Binary Tree Nodes
Medium
30 Points
Tree
Depth-First Search
Breadth-First Search
Union Find
Graph
Binary Tree
You have n binary tree nodes numbered from 0 to n - 1 where node i has two children leftChild[i] and rightChild[i], return true if and only if all the given nodes form exactly one valid binary tree.
If node i has no left child then leftChild[i] will equal -1, similarly for the right child.
Note that the nodes have no values and that we only use the node numbers in this problem.
Examples
Example 1
Input: n = 4, leftChild = [1,-1,3,-1], rightChild = [2,-1,-1,-1]
Output: true
Example 2
Input: n = 4, leftChild = [1,-1,3,-1], rightChild = [2,3,-1,-1]
Output: false
Example 3
Input: n = 2, leftChild = [1,0], rightChild = [-1,-1]
Output: false
Constraints
n == leftChild.length == rightChild.length1 <= n <= 104-1 <= leftChild[i], rightChild[i] <= n - 1
1361. Validate Binary Tree Nodes
Medium
30 Points
Tree
Depth-First Search
Breadth-First Search
Union Find
Graph
Binary Tree
You have n binary tree nodes numbered from 0 to n - 1 where node i has two children leftChild[i] and rightChild[i], return true if and only if all the given nodes form exactly one valid binary tree.
If node i has no left child then leftChild[i] will equal -1, similarly for the right child.
Note that the nodes have no values and that we only use the node numbers in this problem.
Examples
Example 1
Input: n = 4, leftChild = [1,-1,3,-1], rightChild = [2,-1,-1,-1]
Output: true
Example 2
Input: n = 4, leftChild = [1,-1,3,-1], rightChild = [2,3,-1,-1]
Output: false
Example 3
Input: n = 2, leftChild = [1,0], rightChild = [-1,-1]
Output: false
Constraints
n == leftChild.length == rightChild.length1 <= n <= 104-1 <= leftChild[i], rightChild[i] <= n - 1