easyDSA

How do you find the maximum depth of a binary tree?

Q: How do you find the maximum depth of a binary tree?

**Intuition.** The depth of a tree is one more than the depth of its deeper subtree. That's a one-line recursion: depth(node) = 1 + max(depth(left), depth(right)) , with an empty subtree counting as 0. depth = longest root-to-leaf path = 3 levels <circle cx="250" cy="38" r="18" fill="#3b82f6" fill-opacity="0.1

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Explain computing tree height.

treesrecursion

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Recursive height

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class TreeNode:
    def __init__(self, val, left=None, right=None):
        self.val, self.left, self.right = val, left, right

def max_depth(root):
    if not root:
        return 0
    return 1 + max(max_depth(root.left), max_depth(root.right))


# --- demo ---  tree of depth 3
root = TreeNode(3, TreeNode(9), TreeNode(20, TreeNode(15), TreeNode(7)))
print(max_depth(root))   # 3

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