988 Flip Equivalent Binary Trees

Flip Equivalent Binary Trees

For a binary tree T, we can define a flip operation as follows: choose any node, and swap the left and right child subtrees.

A binary tree X is flip equivalent to a binary tree Y if and only if we can make X equal to Y after some number of flip operations.

Given the roots of two binary trees root1 and root2, return true if the two trees are flip equivalent or false otherwise.

 

Example 1:

**Input:** root1 = [1,2,3,4,5,6,null,null,null,7,8], root2 = [1,3,2,null,6,4,5,null,null,null,null,8,7]
**Output:** true
**Explanation: **We flipped at nodes with values 1, 3, and 5.

Example 2:

**Input:** root1 = [], root2 = []
**Output:** true

Example 3:

**Input:** root1 = [], root2 = [1]
**Output:** false

 

Constraints:

The number of nodes in each tree is in the range [0, 100].
Each tree will have **unique node values** in the range [0, 99].

# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, val=0, left=None, right=None):
#         self.val = val
#         self.left = left
#         self.right = right
class Solution:
    def flipEquiv(self, root1: Optional[TreeNode], root2: Optional[TreeNode]) -> bool:
        
        
        def abc(root1, root2):
            
            if (root1 == None and root2 != None) or (root1 != None and root2 == None) :
                return False

            if root1 == None and root2 == None:
                return True

            if root1.val != root2.val:
                return False

            return (abc(root1.right, root2.left) and abc(root1.left, root2.right)) or (abc(root1.left, root2.left) and abc(root1.right, root2.right))

        return abc(root1, root2)