Best stock strategy quiz

gistfile1.rb

prices = []

10.times do
  prices << rand(1..100)
end

p "Today's prices are #{prices.join(', ')}"

min = max = prices.first
profit = 0

buy_in_price = 0
sell_price = 0
best_profit = 0

prices.each_with_index do |price, index|
  if price > max
    max = price
    profit = price - min
  end

  if price < min || index == prices.length - 1
    if profit > best_profit
      buy_in_price = min
      sell_price = max
      best_profit = profit
    end
    min = price
    max = price
    profit = 0
  end
end

if best_profit > 0
  p "The best strategy is to buy in at #{buy_in_price}, and sell at #{sell_price} to earn maximum profit as #{best_profit}"
else
  p "You'd better do nothing today"
end