713196. Tree Transformation
Tree Transformation
Slug: tree-transformation--170645
Difficulty: Medium
Id: 713196
Topic Tags: Tree, Data Structures
Company Tags: None
Summary
The problem involves transforming a given tree into another form. This could be achieved by adding new nodes, removing existing nodes, or rearranging the structure of the tree in some way. The key concepts involved are likely related to tree manipulation and traversal.
Detailed Explanation
The problem can be solved by defining a recursive function that traverses the tree in pre-order, and for each node, it checks if the current node needs to be transformed (in this case, let's say we need to flip the value of each node). If the node needs to be transformed, then recursively call the function on its children. This approach ensures that all nodes are visited exactly once.
Here is a step-by-step breakdown of the solution:
- Initialize an empty tree or a new tree with the same structure as the original one.
- Define a recursive function
transformTreethat takes the root node of the tree as input and returns the transformed tree. - In the
transformTreefunction, recursively traverse the tree in pre-order (root -> left subtree -> right subtree). - For each node visited during traversal:
- Check if the node needs to be transformed (e.g., flip its value).
- If yes, add the transformed node to the new tree.
- Recursively call
transformTreeon the node's children.
Time complexity: O(n), where n is the number of nodes in the tree. This is because we visit each node exactly once during the traversal.
Space complexity: O(n), as we need to store the transformed tree.
Optimized Solutions
Java
public class TreeTransformer {
public static Node transformTree(Node root) {
if (root == null) return null;
// Transform the current node
Node newNode = new Node(root.val * -1); // For example, flip the value
// Recursively call the function on children
newNode.left = transformTree(root.left);
newNode.right = transformTree(root.right);
return newNode;
}
}