find max profit (min loss) to buy and sell within one day stocks prices (Kadane's algo)

daily_stock_profit.rb

def find_buy_sell_stock_prices(array)
  return if !array || !array[1]

  c_buy, g_sell, g_profit, c_profit = array[0], array[1], (array[1] - array[0]), 0
  i = 1

  while i < array.size
    c_profit = array[i] - c_buy

    if c_profit > g_profit
      g_profit = c_profit
      g_sell = array[i]
    end

    c_buy = array[i] if (array[i] < c_buy)
    i += 1
  end
  [g_sell - g_profit, g_sell]
end