Поиск пути по принципу дереваКод на Рубиdef f0(number, log) # v = 1 n = number + v # log = "#{log} + #{v}" log = "#{log} + 1" return [n, log]enddef f1(number, log) # v = 3 n = number * v # log = "#{log} + #{v}" log = "(#{log}) * 3" return [n, log]enddef countWays(start_num, end_num, op_number, max_steps = 0) ways = {} ways.store(start_num.to_s, start_num) max_steps = max_steps == 0 ? (start_num - end_num).abs : max_steps count = 0 for steps in 1..max_steps # puts "steps = #{steps}" new_ways = {} ways.each_pair{|log, num| for k in 0..op_number-1 num1, log1 = f0(num, log) if k == 0 num1, log1 = f1(num, log) if k == 1 if num1 == end_num then log1 += " = " + end_num.to_s count += 1 puts log1 elsif num1.between?(start_num, end_num) new_ways.store(log1, num1) else # log1 = log1 + " = " + num1.to_s + " BAD " # puts log1 end end } # p [steps, ways.size, new_ways.size] ways = new_ways end return countendp countWays(5, 49, 2, 49)Вывод((5) * 3 + 1) * 3 + 1 = 49((5) * 3) * 3 + 1 + 1 + 1 + 1 = 49(5 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1) * 3 + 1 = 49(5 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1) * 3 + 1 + 1 + 1 + 1 = 49(5 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1) * 3 + 1 + 1 + 1 + 1 + 1 + 1 + 1 = 49(5 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1) * 3 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 = 49(5 + 1 + 1 + 1 + 1 + 1 + 1 + 1) * 3 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 = 49(5 + 1 + 1 + 1 + 1 + 1 + 1) * 3 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 = 49(5 + 1 + 1 + 1 + 1 + 1) * 3 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 = 49(5 + 1 + 1 + 1 + 1) * 3 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 = 49(5 + 1 + 1 + 1) * 3 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 = 49(5 + 1 + 1) * 3 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 = 49(5 + 1) * 3 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 = 49(5) * 3 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 = 495 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 = 4915Ответ 15 вариантов программКак это решается аналитически я не знаю, но программно явно быстрее