func maxProfit(prices []int) int {
if len(prices) <= 1 {
return 0
}
buy, sell, sum := prices[0], 0, 0
for _, price := range prices {
if price < sell {
sum += sell - buy
buy, sell = price, 0
} else if price <= buy {
buy = price
} else if price >= sell {
sell = price
}
}
if sell > buy {
sum += sell - buy
}
return sum
}