algorithm/Week_01/id_24/leetcode_687_024.rb at master · algorithm001/algorithm · GitHub

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# Definition for a binary tree node.

# class TreeNode

# attr_accessor :val, :left, :right

# def initialize(val)

# @val = val

# @left, @right = nil, nil

# end

# @param {TreeNode} root

# @return {Integer}

def longest_univalue_path(root)

path_length = 0

get_path_length(root)

return path_length

end

def get_path_length(root)

return 0 if root.nil?

left_path_length = get_path_length(root.left)

right_path_length = get_path_length(root.right)

left_length, right_length = 0, 0

if !root.left.nil? && root.left.val == root.val

left_length = left_path_length + 1

elsif !root.right.nil? && root.right.val == root.val

right_length = right_path_length + 1

end

path_length = [path_length, (left_length + right_length)].max

return [left_length, right_length].max

end

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