// Runtime: 0 ms, faster than 100.00% of Java online submissions for Flip Equivalent Binary Trees.
// Memory Usage: 34.6 MB, less than 100.00% of Java online submissions for Flip Equivalent Binary Trees.

class Solution {
    public boolean flipEquiv(TreeNode root1, TreeNode root2) {
        if (root1 == null || root2 == null) {
            return root1 == root2;
        }

        boolean equiv = root1.val == root2.val;
        if (!equiv) {
            return false;
        }

        boolean le = flipEquiv(root1.left, root2.left);
        boolean re = flipEquiv(root1.right, root2.right);
        if (le && re) {
            return true;
        }

        if (flipEquiv(root1.left, root2.right)) {
            return flipEquiv(root1.right, root2.left);
        }
        return false;
    }
}