lib/easy/111_minimum_depth_of_binary_tree.rb

# frozen_string_literal: true

# https://leetcode.com/problems/minimum-depth-of-binary-tree/
# @param {TreeNode} root
# @return {Integer}
def min_depth(root)
  return 0 if root.nil?

  return 1 if root.left.nil? && root.right.nil?

  return min_depth(root.right) + 1 if root.left.nil?

  return min_depth(root.left) + 1 if root.right.nil?

  [min_depth(root.left) + 1, min_depth(root.right) + 1].min
end