Question

我将以下code尽可能地从Java翻译成C＃：

public double maxProfit(double[] prices, int K)
        {
            if (K == 0 || prices.Length == 0)
            {
                return 0;
            }

            var dp = new double[K + 1, prices.Length];

            for (int i = 1; i < K + 1; i++)
            {
                double maxDiff = -prices[0];
                for (int j = 1; j < prices.Length; j++)
                {
                    dp[i, j] = Math.Max(dp[i, j - 1], prices[j] + maxDiff);
                    maxDiff = Math.Max(maxDiff, dp[i - 1, j] - prices[j]);
                }
            }

            printTrans(dp, prices, K);


            return dp[K, prices.Length - 1];
        }

        public void printTrans(double[,] dp, double[] prices, int K)
        {
            int i = K - 1;
            int j = prices.Length;

            var priceList = new List<double>();
            while (true)
            {
                if (i == 0 || j == 0)
                {
                    break;
                }

                if (dp[i, j] == dp[i, j - 1])
                {
                    j = j - 1;
                }
                else
                {
                    priceList.Add(j);
                    double maxDiff = dp[i, j] - prices[j];
                    for (int z = j - 1; z >= 0; z--)
                    {
                        if (dp[i - 1, z] - prices[z] == maxDiff)
                        {
                            i = i - 1;
                            j = z;
                            priceList.Add(j);
                            break;
                        }
                    }
                }
            }

            while (priceList.Count > 0)
            {
                Console.WriteLine("Buy @ " + prices[priceList.IndexOf(0)]);
                Console.WriteLine("Sell @ " + prices[priceList.IndexOf(0)]);
            }
        }

第二行方法出现错误：

if (dp[i, j] == dp[i, j - 1])

和

 for (int z = j - 1; z >= 0; z--)
  {
   if (dp[i - 1, z] - prices[z] == maxDiff)

我得到Index was outside the bounds of the array。错误。我理解这个错误意味着什么，但我不知道我要解决它。我花了很多时间来理解这段代码的第一部分，但对于第二部分，我感到很茫然。

还有什么是Java pollFirst()方法的C＃等价物？

Answer 1

可能这一行是原因

 public void printTrans(double[,] dp, double[] prices, int K)
        {
            int i = K - 1;
            int j = prices.Length; // <=== this line is the cause

导致j引用超出2D数组范围的索引。

如果您已从java移植，请重新检查您的java代码。

要么划线

int j = prices.Length - 1;

或者您需要更改创建阵列的方式

 var dp = new double[K + 1, prices.Length]; // <-- prices.Length would have to change here

股票最大化算法边界外的指数

1 个答案: