Answer Happy

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.
/**
* Definition for a binary tree node.
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode() : val(0), left(nullptr),
right(nullptr) {}
* TreeNode(int x) : val(x), left(nullptr),
right(nullptr) {}
* TreeNode(int x, TreeNode *left, TreeNode
*right) : val(x), left(left), right(right) {}
* };
*/
class FindElements {
public:
FindElements(TreeNode* root) {

}

bool find(int target) {

}
};
/**
* Your FindElements object will be instantiated and called as
such:
* FindElements* obj = new FindElements(root);
* bool param_1 = obj->find(target);
*/