<jupyter_start><jupyter_text>Given the root nodes of two binary trees, determine if they are identical.Clarifying questions:* What does it mean for two binary trees to be identical? (In this case, same node structure and same values in each node.)Initial thoughts:* A DFS approach would make the most sense.* Each node can be checked for equality. Are the values equal? Do the children have equal values? Etc.* We can check for equality recursively.Recursive DFS pseudocode:1. Recursively perform DFS on the left node if it exists.2. Evaluate the current node.3. Recursively perform DFS on the right node if it exists.In this case, evaluation would be check for node equality.Node equality pseudocode:1. If node1.val != node2.val, return false.2. If they don't have the same number of children, return false.Let's try coding it out.<jupyter_code>def are_trees_identical(node1, node2):
    if node1.val != node2.val:
        return False
    node1_children = node2_children = 0
    if node1.left:
        node1_children += 1
    if node1.right:
        node1_children += 1
    if node2.left:
        node2_children += 1
    if node2.right:
        node2_children += 1
    if node1_children != node2_children:
        return False
    
    # recursively check left subtrees
    if node1.left and node2.left:
        if not are_trees_identical(node1.left, node2.left):
            return False
    
    # recursively check right subtrees
    if node1.right and node2.right:
        if not are_trees_identical(node1.right, node2.right):
            return False
    
    return True<jupyter_output><empty_output>
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