solution.cpp

/**
 * 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) {}
 * };
 */

/**
 * 76 / 76 test cases passed.
 * Runtime: 12 ms
 * Memory Usage: 11.7 MB 
 */
class Solution {
public:
    bool flipEquiv(TreeNode* root1, TreeNode* root2) {
        if (!root1 && !root2) return true;
        if (!root1 && root2 || root1 && !root2) return false;
        if (root1->val != root2->val) return false;
        return flipEquiv(root1->right, root2->right) && flipEquiv(root1->left, root2->left) ||
                flipEquiv(root1->right, root2->left) && flipEquiv(root1->left, root2->right);
    }
};