714276. Subtree In N-ary Tree
Subtree In N-ary Tree
Summary
Given an n-ary tree, we need to find all the subtrees that are identical to a given subtree. An n-ary tree is a rooted tree in which each node has at most n children. This problem involves traversing the n-ary tree and comparing nodes.
Detailed Explanation
To solve this problem, we will use depth-first search (DFS) traversal of the n-ary tree. We will recursively visit each child node of the current node. If we find a subtree that matches the given subtree, we will add it to our result list.
Here is a step-by-step breakdown of the solution:
- Initialize an empty result list
result. - Define a recursive function
findSubtreesthat takes two parameters: the root of the n-ary tree and the given subtree. - In the
findSubtreesfunction:- Traverse each child node of the current node using DFS.
- For each child node, recursively call
findSubtreeswith the child node as the new root and the given subtree. - If a match is found, add it to the result list.
- Return the result list.
The time complexity of this solution is O(N), where N is the number of nodes in the n-ary tree. This is because we visit each node once while traversing the tree. The space complexity is also O(N) due to the recursion stack.
Optimized Solutions
Here are optimized solutions in Java, Python, C++, and JavaScript:
Java
import java.util.*;
class Node {
int val;
List<Node> children;
public Node(int _val) {
val = _val;
children = new ArrayList<>();
}
}
public class Main {
public static List<Node> findSubtrees(Node root, Node target) {
List<Node> result = new ArrayList<>();
findSubtreesHelper(root, target, result);
return result;
}
private static void findSubtreesHelper(Node node, Node target, List<Node> result) {
if (node == null || !isMatch(node, target)) return;
if (areIdentical(node, target)) result.add(node);
for (Node child : node.children) {
findSubtreesHelper(child, target, result);
}
}
private static boolean isMatch(Node node, Node target) {
// Check if the current node matches the target subtree
return false; // Implement your matching logic here
}
private static boolean areIdentical(Node node1, Node2) {
// Check if two nodes are identical (same value and children)
return false; // Implement your comparison logic here
}
}