#111

Minimum Depth of Binary Tree

easy · verified · 52.4% accepted · 7,816 likes · top 42%

tree · depth-first search · breadth-first search · binary tree

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Description

Given a binary tree, find its minimum depth.

The minimum depth is the number of nodes along the shortest path from the root node down to the nearest leaf node.

Note: A leaf is a node with no children.

Example 1:

Input: root = [3,9,20,null,null,15,7]
Output: 2

Example 2:

Input: root = [2,null,3,null,4,null,5,null,6]
Output: 5

Solution