全10種類のコンプガチャ1回300円、全種類コンプまでどれだけお金をするのかシミュレーション。当選確率は一様にしてあるため実際はこれよりだいぶひどい結果が出ると思われる。notepad++で書いたのでタブ幅は2ではない

gacha_comp_simulation.rb

#! /usr/bin/ruby -Ku

include Math

KINDS = 10	# 景品の種類
COST = 300	# 一回の料金
	
class Gacha

	def initialize()
		@trial = 0
		@total = 0
		s = Array.new(KINDS, false)
		
		while !fullfill?(s)
			r = rand(KINDS).floor
			s[r] = true
			@total += COST
			@trial += 1
		end
	end
	
	def fullfill?(set)
		ret = true
		set.each do |i|
			ret &= i
		end
		return ret
	end

	def inspect
		return sprintf "try: %5d, cost: %8d", @trial, @total
	end
	
	attr_reader :trial, :total
end
	
class GachaTest

	def initialize(n=0)
		count = 0
		@n = n
		@@average_cost = 0.0
		@@average_trial = 0
		
		while count < n
			g = Gacha.new
			@@average_cost += g.total
			@@average_trial += g.trial
			count += 1
			
			p g
		end
	end
	
	def inspect
		return sprintf "\ntest num: %d\n\taverage trial: %5.3f, average cost: %5.3f", @n, @@average_trial / @n, @@average_cost / @n
	end
end

p GachaTest.new(10000)