1602. Find Nearest Right Node in Binary Tree

Given the root of a binary tree and a node u in the tree, return the nearest node on the same level that is to the right of u, or return null if u is the rightmost node in its level.

/**
 * 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 Solution {
    bool find = false;
    int targetLevel = -1;
public:
    TreeNode* findNearestRightNode(TreeNode* root, TreeNode* u, bool moveRight = false, int level = 0) {
        if(!root) return nullptr;
        
        if(find) {
            if(level == targetLevel) return root;
            if(moveRight) {
                auto res = findNearestRightNode(root->left, u, moveRight, level + 1);
                if(res) return res;
            } 
            return findNearestRightNode(root->right, u, true, level + 1);
        }
        if(root == u) {
            find = true;
            targetLevel = level;
            return nullptr;
        }
        
        auto res = findNearestRightNode(root->left, u, false, level + 1);
        if(find and res != nullptr) {
            return res;
        }
        
        return findNearestRightNode(root->right, u, find, level + 1);
    }
};