[LeetCode]Best Time to Buy and Sell Stock with Transaction Fee

用DP[i]表示前i + 1天的最大利润，我们有递推公式：

• localMax = max(max(dp[j - 1] + prices[i] - prices[j] - fee), prices[i] - prices[0] - fee), where 1 <= j < i
• dp[i] = max(dp[i - 1], localMax)

递推公式取dp[j - 1] + prices[i] - prices[j] - fee或者dp[j] + prices[i] - prices[j] - fee都是可以的，不会影响最终的结果。时间复杂度O(n)，空间复杂度O(n):

我们可以优化到常数空间，代码如下：