maximum-depth-of-binary-tree

Maximum Depth of Binary Tree

Given a binary tree, find its maximum depth.

The maximum depth is the number of nodes along the longest path from the root node down to the farthest leaf node.

Note: A leaf is a node with no children.

Example:

Given binary tree [3,9,20,null,null,15,7],

    3
   / \
  9  20
    /  \
   15   7
return its depth = 3.

Complexity Analysis:

• Time complexity : O(n). We visit each node in the tree exactly once.

• Space complexity : O(log(n)) - best, o(n) worst. The best case is for a completely balanced tree. The worst case is for an unbalanced tree. The space is to keep a recursion stack.

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