格闘ゲーム : https://paiza.jp/works/mondai/class_primer/class_primer__fighting_game

input.txt

5 10
8 2 24 40 25 42 26
59 48 13 21 13 56 2
5 59 7 57 5 25 24
99 28 6 32 5 23 2
62 24 19 11 19 7 21
2 1 3 2
2 1 3 2
5 1 3 1
5 3 1 2
1 1 2 2
4 2 3 1
5 3 3 2
2 3 3 2
4 1 5 3
2 3 3 2

main.rb

# frozen_string_literal: true

# 戦士
# 体力があり、3つの攻撃スキルを持っている
class Fighter
  attr_reader :id, :skills
  attr_accessor :health

  def initialize(id, health, skills)
    @id = id
    @health = health
    @skills = skills
    @current_skill = nil
  end

  def attack_skill(index)
    @current_skill = skills_at(index)
  end

  def attack_power
    @current_skill.attack_power
  end

  def attack_delay
    @current_skill.attack_delay
  end

  def available_to_fight?
    health.positive?
  end

  private

  def skills_at(index)
    special_attack! if special_attack?(index)

    @skills.at(index - 1)
  end

  def special_attack?(index)
    @skills.at(index - 1).then(&:special_attack?)
  end

  def special_attack!
    @skills.each(&:obtain_buff!)
  end
end

class Fighter
  # 戦士が使う攻撃スキル
  # 攻撃速度と攻撃力を持っている
  # 攻撃速度と攻撃力がゼロの場合は、強化技を表す
  class AttackSkill
    ATTACK_SPEED_BUFF = -3
    ATTACK_POWER_BUFF = 5

    attr_reader :attack_delay, :attack_power

    def initialize(attack_delay, attack_power)
      @attack_delay = attack_delay
      @attack_power = attack_power
    end

    def special_attack?
      attack_delay.zero? && attack_power.zero?
    end

    # スキルを強化する
    # 攻撃速度と攻撃力が上昇する
    def obtain_buff!
      return if special_attack? # 強化技自身の場合は何もしない

      @attack_delay += ATTACK_SPEED_BUFF
      @attack_power += ATTACK_POWER_BUFF

      @attack_delay = 1 if @attack_delay <= 0 # 攻撃速度が速くなりすぎないように補正を入れる
    end
  end
end

# 戦闘ステージ
# 体力の続く限り、戦士同士を戦わせて、最後に生き残った戦士の数を返す
class FightStage
  def initialize(fighters, attacks_rounds)
    @fighters = fighters
    @attack_rounds = attacks_rounds
  end

  def fight!
    run_fight_loop!

    @fighters.find_all(&:available_to_fight?).size
  end

  private

  # 指定されたインデックスに対応する戦士とスキルを取得・設定する
  def find_fighter_and_set_skill(fighter_id, skill_index)
    fighter = @fighters.find { _1.id.eql?(fighter_id) }
    fighter.attack_skill(skill_index)

    fighter
  end

  # 戦闘に参加する2組の戦士を取得する
  def find_fighters(attack_round)
    attack_round.fighters.map do |fighter|
      find_fighter_and_set_skill(*fighter)
    end
  end

  def run_fight_loop!
    @attack_rounds.each do |attack_round|
      fighter1, fighter2 = find_fighters(attack_round)

      # どちらかが戦闘不能の場合、なにもしない
      next unless [fighter1, fighter2].any?(&available_to_fight?)

      # 攻撃速度に応じて、どちらの戦士が攻撃できるかを判定する
      # 攻撃速度が相手より優っている場合は、相手の体力を削る事が出来る
      if fighter1.attack_delay.eql?(fighter2.attack_delay)
        # なにもしない
      elsif fighter1.attack_delay < fighter2.attack_delay
        fighter2.health -= fighter1.attack_power
      else
        fighter1.health -= fighter2.attack_power
      end
    end
  end
end

class FightStage
  # 戦士が戦う相手とスキル、それぞれ1回戦分を保持する
  class AttackRound
    attr_reader :fighter1_id, :skill1_index, :fighter2_id, :skill2_index

    def initialize(fighter1_id, skill1_index, fighter2_id, skill2_index)
      @fighter1_id = fighter1_id
      @skill1_index = skill1_index
      @fighter2_id = fighter2_id
      @skill2_index = skill2_index
    end

    def fighter1
      [@fighter1_id, @skill1_index]
    end

    def fighter2
      [@fighter2_id, @skill2_index]
    end

    def fighters
      [fighter1, fighter2]
    end
  end
end

# メイン処理
# 戦士達のステータスやスキル情報・行動取得と戦闘ステージでの戦闘を実行する
class Solver
  def solve!
    input

    fight_stage = FightStage.new(@fighters, @attack_rounds)

    fight_stage.fight!
  end

  private

  def input
    @number_of_fighters, @number_of_rounds = gets.chomp.split.map(&:to_i)

    input_fighters
    input_attack_rounds
  end

  def input_fighters
    @fighters =
      @number_of_fighters.times.map do |index|
        health, *attack_elements = splat_fighter_params

        attack_skills =
          attack_elements.map do |attack_delay, attack_power|
            Fighter::AttackSkill.new(attack_delay, attack_power)
          end

        Fighter.new(index + 1, health, attack_skills)
      end
  end

  # 戦士達が、誰に対してどのスキルを使い、戦いを進めていくかを取得する
  # ここでは 2人の戦士のIDと、それぞれのスキルのインデックスを取得する
  def input_attack_rounds
    @attack_rounds =
      @number_of_rounds.times.map do
        fighter1, skill1, fighter2, skill2 = gets.split.map(&:to_i)

        FightStage::AttackRound.new(fighter1, skill1, fighter2, skill2)
      end
  end

  # 戦士の体力と3つのスキルを取得する
  def splat_fighter_params
    health, *params = gets.split.map(&:to_i)

    attack_delay1, attack_power1, *params = params
    attack_delay2, attack_power2, *params = params
    attack_delay3, attack_power3 = params

    [
      health,
      [attack_delay1, attack_power1],
      [attack_delay2, attack_power2],
      [attack_delay3, attack_power3]
    ]
  end
end

solver = Solver.new

#
# ruby main.rb < input.txt
#
puts solver.solve! # => 3