package q714

// Note: could be done faster with dynamic programming

func maxProfit(prices []int, fee int) int {
	var low, high, profit int
	bought := false
	for i := range prices {
		if bought {
			high = max(high, prices[i])
			if high-prices[i] > fee { // should have sold earlier or not bought
				if high-low > fee {
					profit += high - low - fee
				}
				bought = false
			} else if prices[i] < low { // regret buying too early
				low, high = prices[i], prices[i]
			}
		}

		if !bought && i < len(prices)-1 && prices[i+1] > prices[i] {
			bought = true // buy the dip
			low, high = prices[i], prices[i]
		}
	}

	if bought && high-low > fee {
		profit += high - low - fee
	}
	return profit
}

var _ = maxProfit