Explanation:Buy on day 2 (price = 1) and sell on day 3 (price = 5), profit = 5-1 = 4. Then buy on day 4 (price = 3) and sell on day 5 (price = 6), profit = 6-3 = 3. Total profit is 4 + 3 = 7.
Example 2:
Input:prices = [1,2,3,4,5]
Output:4
Explanation:Buy on day 1 (price = 1) and sell on day 5 (price = 5), profit = 5-1 = 4. Total profit is 4.
Example 3:
Input:prices = [7,6,4,3,1]
Output:0
Explanation:There is no way to make a positive profit, so we never buy the stock to achieve the maximum profit of 0.