714517. Tree Transformation
Medium
Tree Transformation
Summary
The Tree Transformation problem involves transforming a tree into another tree based on specific rules. The task is to write an algorithm that takes a given tree as input and returns the transformed tree. This problem requires understanding of tree traversal techniques, node manipulation, and data structure operations.
Detailed Explanation
Given a tree T, we need to transform it into another tree T' by applying certain operations. These operations include:
- For each node in T, if its value is even, change it to the next multiple of 4.
- If the value is odd, change it to the next multiple of 3.
We can solve this problem using a depth-first search (DFS) algorithm. Here's a step-by-step breakdown of the solution:
- Start at the root node and perform DFS traversal.
- For each node, check if its value is even or odd.
- If the value is even, calculate the next multiple of 4 and update the node's value.
- If the value is odd, calculate the next multiple of 3 and update the node's value.
- Recursively traverse the left subtree and then the right subtree.
- Repeat steps 2-5 until all nodes have been processed.
Time complexity: O(N), where N is the number of nodes in the tree. Space complexity: O(H), where H is the height of the tree (in a balanced binary tree, H = logN).
Optimized Solutions
Java
class TreeNode {
int val;
TreeNode left;
TreeNode right;
public TreeNode(int val) {
this.val = val;
this.left = null;
this.right = null;
}
}
public class TreeTransformer {
public static TreeNode transformTree(TreeNode root) {
if (root == null) return null;
int newVal = (root.val % 2 == 0) ? root.val + (4 - root.val % 4) : root.val + (3 - root.val % 3);
root.val = newVal;
root.left = transformTree(root.left);
root.right = transformTree(root.right);
return root;
}
}