/**
 * Definition for a binary tree node.
 * public class TreeNode {
 * int val;
 * TreeNode left;
 * TreeNode right;
 * TreeNode() {}
 * TreeNode(int val) { this.val = val; }
 * TreeNode(int val, TreeNode left, TreeNode right) {
 * this.val = val;
 * this.left = left;
 * this.right = right;
 * }
 * }
 */
class Solution {
    public boolean flipEquiv(TreeNode root1, TreeNode root2) {
        if (root1 == null && root2 == null)
            return true;
        if (root1 == null || root2 == null)
            return false;
        return (flipEquiv(root1.left, root2.left) && flipEquiv(root1.right, root2.right))
                || (flipEquiv(root1.left, root2.right) && flipEquiv(root1.right, root2.left));
    }
}