Leetcode Solutions Java Python C++
All contents and pictures on this website come from the Internet and are updated regularly every week. They are for personal study and research only, and should not be used for commercial purposes. Thank you for your cooperation.
Welcome to Subscribe On Youtube:

1483. Kth Ancestor of a Tree Node

You are given a tree with n nodes numbered from 0 to n-1 in the form of a parent array where parent[i] is the parent of node i. The root of the tree is node 0.

Implement the function getKthAncestor(int node, int k) to return the k-th ancestor of the given node. If there is no such ancestor, return -1.

The k-th ancestor of a tree node is the k-th node in the path from that node to the root.

 

Example:

Input:
["TreeAncestor","getKthAncestor","getKthAncestor","getKthAncestor"]
[[7,[-1,0,0,1,1,2,2]],[3,1],[5,2],[6,3]]

Output:
[null,1,0,-1]

Explanation:
TreeAncestor treeAncestor = new TreeAncestor(7, [-1, 0, 0, 1, 1, 2, 2]);

treeAncestor.getKthAncestor(3, 1);  // returns 1 which is the parent of 3
treeAncestor.getKthAncestor(5, 2);  // returns 0 which is the grandparent of 5
treeAncestor.getKthAncestor(6, 3);  // returns -1 because there is no such ancestor

 

Constraints:

  • 1 <= k <= n <= 5*10^4
  • parent[0] == -1 indicating that 0 is the root node.
  • 0 <= parent[i] < n for all 0 < i < n
  • 0 <= node < n
  • There will be at most 5*10^4 queries.

Difficulty:

Hard

Lock:

Normal

Company:

Google

Problem Solution

1483-Kth-Ancestor-of-a-Tree-Node

All Problems:

Link to All Problems
All contents and pictures on this website come from the Internet and are updated regularly every week. They are for personal study and research only, and should not be used for commercial purposes. Thank you for your cooperation.