1261 - Find Elements in a Contaminated Binary Tree.

Medium

Given a binary tree with the following rules:

• root.val == 0

• If treeNode.val == x and treeNode.left != null, then treeNode.left.val == 2 * x + 1

• If treeNode.val == 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

Constraints:

• TreeNode.val == -1

• The height of the binary tree is less than or equal to 20

• The total number of nodes is between <code>1, 10⁴</code>

• Total calls of find() is between <code>1, 10⁴</code>

• <code>0 <= target <= 10⁶</code>