java - 我的 "find median"实现中有什么错误？

Question

我发现有人有类似的问题( How to calculate the median of an array? )，但我不知道如何将其合并到我自己的代码中，因为我对 java 相当陌生。现在，我的 findmedian 方法返回 0 而不是实际的中位数，我似乎无法弄清楚。谢谢!

import java.util.Scanner;
import java.util.Arrays;

public class Original
{
    public static void main(String[] args)
    {
        Scanner inputNumber = new Scanner(System.in);
        Scanner dataItem = new Scanner(System.in);
        Scanner input = new Scanner(System.in);

        System.out.print("This stores a list of contirbutions to a charity drive.\n ");
        System.out.print("How many contributors will be entered? ");

        double contributors = inputNumber.nextDouble();
        double contributions[ ] = new double[50];  
        double contributions_check[] = findData (contributors, contributions);

        System.out.print("See if the contributions are correct. ");

        // Displays the contributions, loop allows numbers to be displayed correctly
        for (int count = 0; count < contributors; count++) {
            System.out.print(contributions_check[count] + "    ");
        }

        double median = findmedian(contributors,contributions_check);
        System.out.print("\n The median contribution is: " + median);
    }

    public static double[] findData(double n, double[] contributions2)
    {
        Scanner dataItem = new Scanner(System.in);

        // x must be 0 and x must be < than n
        for (int x = 0; x < n; x++) {
            System.out.print("Please enter the next contribution: ");
            contributions2[x] = dataItem.nextDouble();
        }

        return contributions2;
    }

    public static double findmedian(double n, double data[])
    {
        Arrays.sort(data);
        double median;

        if (data.length % 2 == 0) {
            median = ((double) data[data.length / 2] +
                      (double) data[data.length / 2 - 1]) / 2;
        } else {
            median = (double) data[data.length/2];
        }

        return median;
    }
}

Answer 1

我认为问题是您在 findmedian 中使用 data.length，而您应该在其中使用 n。 data.length 始终为 50，即使您只输入了 5 个项目......