Question

我正在进行冒泡练习，我的感觉是非常接近正确。就在此刻，我被呈现出一个永恒的循环。

错误在哪里？

static void Main(string[] args)
    {
        int[] numbers = { 2, 4, 8, 5, 88, 55, 32, 55, 47, 8, 99, 120, 4, 32 };
        int temporary;
        bool sorted;
        do
        {
            sorted = false;

            for (int i = 0; i < numbers.Length - 1; i++)
            {
                int a = numbers[i];
                int b = numbers[i + 1];
                if (a > b)
                {
                    temporary = a;
                    a = b;
                    b = temporary;

                    sorted = true;

                }
            }
            Console.WriteLine("sorted");
        } while (sorted == true);


        foreach (int i in numbers)
        {
            Console.Write(i + " ");
        }

    }

Answer 1

C＃中更好的方法是使用通用冒泡排序

public void BubbleSort<T>(IList<T> list);
{
    BubbleSort<T>(list, Comparer<T>.Default);
}

public void BubbleSortImproved<T>(IList<T> list, IComparer<T> comparer)
{
    bool stillGoing = true;
    int k = 0;
    while (stillGoing)
    {
        stillGoing = false;
        for (int i = 0; i < list.Count - 1 - k; i++)
        {
            T x = list[i];
            T y = list[i + 1];
            if (comparer.Compare(x, y) > 0)
            {
                list[i] = y;
                list[i + 1] = x;
                stillGoing = true;
            }
        }
        k++;
    }
}

Jon Skeet在answer here中给出了该算法的简要说明。 “它使用任意比较器，但允许你省略它，在这种情况下，默认比较器用于相关类型。它将对IList的任何（非只读）实现进行排序，包括数组。”

我希望这会有所帮助。

Answer 2

您与a交换b，但您不对输入数组执行任何操作。因此，您不断在内存中交换值，但原始数组不会更改。尝试：

            for ( int i = 0; i < numbers.Length - 1; i++ )
            {
                if ( numbers[i] > numbers[i + 1] )
                {
                    temporary = numbers[i];
                    numbers[i] = numbers[i + 1];
                    numbers[i + 1] = temporary;

                    sorted = true;

                }
            }

Answer 3

您没有将结果写回数组。

请改用：

//temporary = a;
//a = b;
//b = temporary;

numbers[i] = b;
numbers[i + 1] = a;

Answer 4

应该是

if (numbers[i] > numbers[i + 1])
    {
            temporary = numbers[i];
            numbers[i] = numbers[i + 1];
            numbers[i + 1] = temporary;

            sorted = true;

     }

a，b所做的更改并未反映在numbers[i] numbers[i+1]中，因为a和b仅为copy numbers[i] } numbers[i+1] ..

Answer 5

以下是一个工作示例：

static void Main(string[] args)
{
    int[] numbers = { 2, 4, 8, 5, 88, 55, 32, 55, 47, 8, 99, 120, 4, 32 };
    int temporary;
    bool sorted;

    do
    {
        sorted = false;
        for (int i = 0; i < numbers.Length - 1; i++)
        {
            if (numbers[i] > numbers[i + 1])
            {

                temporary = numbers[i];
                numbers[i] = numbers[i + 1];
                numbers[i + 1] = temporary;

                sorted = true;
            }
        }
        Console.WriteLine("sorted");
    } while (sorted == true);

    foreach (int i in numbers)
    {
        Console.Write(i + " ");
    }
}

泡沫排序背后的逻辑

5 个答案: