#1261

Find Elements in a Contaminated Binary Tree

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hash table · tree · depth-first search · breadth-first search · design · binary tree

Description

Given a binary tree with the following rules:

- root.val == 0

- For any treeNode:

- If treeNode.val has a value x and treeNode.left != null, then treeNode.left.val == 2 * x + 1

- If treeNode.val has a value x and treeNode.right != null, then treeNode.right.val == 2 * x + 2

Now the binary tree is contaminated, which means all treeNode.val have been changed to -1.

Implement the FindElements class:

- FindElements(TreeNode* root) Initializes the object with a contaminated binary tree and recovers it.

- bool find(int target) Returns true if the target value exists in the recovered binary tree.

Example 1:

Input

["FindElements","find","find"]

[[[-1,null,-1]],[1],[2]]

Output

[null,false,true]

Explanation

FindElements findElements = new FindElements([-1,null,-1]);

findElements.find(1); // return False

findElements.find(2); // return True

Example 2:

Input

["FindElements","find","find","find"]

[[[-1,-1,-1,-1,-1]],[1],[3],[5]]

Output

[null,true,true,false]

Explanation

FindElements findElements = new FindElements([-1,-1,-1,-1,-1]);

findElements.find(1); // return True

findElements.find(3); // return True

findElements.find(5); // return False

Example 3:

Input

["FindElements","find","find","find","find"]

[[[-1,null,-1,-1,null,-1]],[2],[3],[4],[5]]

Output

[null,true,false,false,true]

Explanation

FindElements findElements = new FindElements([-1,null,-1,-1,null,-1]);

findElements.find(2); // return True

findElements.find(3); // return False

findElements.find(4); // return False

findElements.find(5); // return True

Solution