LeetCode Add Two Numbers を解いてみた

問題

leetcode.com

解いた

# Definition for singly-linked list.
# class ListNode
#     attr_accessor :val, :next
#     def initialize(val = 0, _next = nil)
#         @val = val
#         @next = _next
#     end
# end
# @param {ListNode} l1
# @param {ListNode} l2
# @return {ListNode}

def get_list(list_node)
    result = []
    result << list_node.val
    loop do
      next_node = list_node.next
      if next_node.nil?
          break
      end
      result << next_node.val
      list_node = next_node
    end
    result 
end

def add_two_numbers(l1, l2)
    sum_arr = []
    l1_list = get_list(l1)
    l2_list = get_list(l2)
    move_up_flag = false
    
    long_arr = l1_list.length >= l2_list.length ? l1_list : l2_list
    short_arr = long_arr == l1_list ? l2_list : l1_list
    
    long_arr.each_with_index do |long_num, index|
        short_num = short_arr[index].nil? ? 0 : short_arr[index]
        sum = long_num + short_num
        if move_up_flag 
            sum += 1
            move_up_flag = false
        end
        
        if sum >= 10
            sum -= 10
            move_up_flag = true
        end
        sum_arr << sum
    end
    if move_up_flag
        sum_arr << 1
    end
    p sum_arr
end

結果

うーーん。遅い。