MergeSort java 图形表示

Question

您好，我有合并排序类，我想绘制排序数组的直方图，当尝试从屏幕上的排序类中检索数据时，只出现未排序的数组，然后是排序的数组。我必须如何重组我的排序类，以便在每次排序时返回完整的数组，或者我如何检索合并（数组，左，右）（我认为这是我必须用来创建直方图的部分）

package mergeSort;


import java.util.*;

public class MergeSort {
    public static void main(String[] args) {
        int[] list = {14, 32, 67, 76, 23, 41, 58, 85};
        System.out.println("before: " + Arrays.toString(list));
        mergeSort(list);
        System.out.println("after:  " + Arrays.toString(list));
    }

    public static void mergeSort(int[] array) {
        if (array.length > 1) {
            // split array into two halves
            int[] left = leftHalf(array);
            int[] right = rightHalf(array);

            // recursively sort the two halves
            mergeSort(left);
            mergeSort(right);

            // merge the sorted halves into a sorted whole
            merge(array, left, right);
        }
    }

    // Returns the first half of the given array.
    public static int[] leftHalf(int[] array) {
        int size1 = array.length / 2;
        int[] left = new int[size1];
        for (int i = 0; i < size1; i++) {
            left[i] = array[i];
        }
        return left;
    }

    // Returns the second half of the given array.
    public static int[] rightHalf(int[] array) {
        int size1 = array.length / 2;
        int size2 = array.length - size1;
        int[] right = new int[size2];
        for (int i = 0; i < size2; i++) {
            right[i] = array[i + size1];
        }
        return right;
    }

    public static void merge(int[] result, int[] left, int[] right) {
        int i1 = 0;   // index into left array
        int i2 = 0;   // index into right array

        for (int i = 0; i < result.length; i++) {
            if (i2 >= right.length || (i1 < left.length && 
                    left[i1] <= right[i2])) {
                result[i] = left[i1];    // take from left
                i1++;
            } else {
                result[i] = right[i2];   // take from right
                i2++;
            }
        }
    }
 }

另外，当我调用冒泡排序时，一切正常，所以我认为我必须重组 mergeClass 如果你有想法请分享谢谢

这是我的打印方法

int Value = 100;
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        int edge= 50;
        for (int i = 0; i < array.length; i++) {
            g.drawLine(i + offSet, Value + edge, i + edge,
                    Value + edge- array[i]);
        }
    }

冒泡排序

    public void bubbleSort(int[] a) throws InterruptedException {
    for (int i = 0; i < a.length; i++) {
        for (int j = 1; j < (a.length - i); j++) {
            if (a[j - 1] > a[j])
                swap(a, j - 1, j);
        }
    }
}

Answer 1

记录每个步骤（而不是返回每个步骤）就足够了吗？如果是这样，以下将为您提供一个 int[] 数组列表，每个数组都存储排序过程的每个步骤的值。然后，您可以遍历列表并在闲暇时显示它。
以下：

package mergeSort;


import java.util.*;

public class MergeSort {

    public static void main(String[] args) {
        int[] list = {14, 32, 67, 76, 23, 41, 58, 85};

        List<int[]> listOfLists = new ArrayList<int[]>();

        System.out.println("before: " + Arrays.toString(list));
        mergeSort(list,listOfLists);
        System.out.println("after:  " + Arrays.toString(list));

        System.out.println("Each step:");
        for(int[] arrList : listOfLists)
            System.out.println(Arrays.toString(arrList));
    }

    public static void mergeSort(int[] array, List<int[]> listOfLists) {
        if (array.length > 1) {
            // split array into two halves
            int[] left = leftHalf(array);
            int[] right = rightHalf(array);

            // recursively sort the two halves
            mergeSort(left,listOfLists);
            mergeSort(right,listOfLists);

            // merge the sorted halves into a sorted whole
            merge(array, left, right);
            listOfLists.add(array);

        }
    }

    // Returns the first half of the given array.
    public static int[] leftHalf(int[] array) {
        int size1 = array.length / 2;
        int[] left = new int[size1];
        for (int i = 0; i < size1; i++) {
            left[i] = array[i];
        }
        return left;
    }

    // Returns the second half of the given array.
    public static int[] rightHalf(int[] array) {
        int size1 = array.length / 2;
        int size2 = array.length - size1;
        int[] right = new int[size2];
        for (int i = 0; i < size2; i++) {
            right[i] = array[i + size1];
        }
        return right;
    }

    public static void merge(int[] result, int[] left, int[] right) {
        int i1 = 0;   // index into left array
        int i2 = 0;   // index into right array

        for (int i = 0; i < result.length; i++) {
            if (i2 >= right.length || (i1 < left.length && 
                    left[i1] <= right[i2])) {
                result[i] = left[i1];    // take from left
                i1++;
            } else {
                result[i] = right[i2];   // take from right
                i2++;
            }
        }
    }
 }

会返回这个：

before: [14, 32, 67, 76, 23, 41, 58, 85]
after:  [14, 23, 32, 41, 58, 67, 76, 85]
Each step:
[14, 32]
[67, 76]
[14, 32, 67, 76]
[23, 41]
[58, 85]
[23, 41, 58, 85]
[14, 23, 32, 41, 58, 67, 76, 85]

Answer 2

好的，我想我明白你的问题了。这对你有用吗？在我放置 println 语句的地方，您可以改为呈现当前数组。

package mergeSort;

import java.util.Arrays;

public class MergeSort {

    public static void main(String[] args) {
        int[] list = { 14, 32, 76, 67, 41, 23, 58, 85 };

        System.out.println("before: " + Arrays.toString(list));
        mergeSort(list, 0, list.length - 1);
        System.out.println("after:  " + Arrays.toString(list));

    }

    public static void mergeSort(int[] array, int left, int right) {
        int mid = 0;

        if (right > left) {
            mid = (right + left) / 2;

            // sort left
            mergeSort(array, left, mid);
            // sort right
            mergeSort(array, mid + 1, right);
            // merge them
            merge(array, left, mid+1, right);

            // PUT YOUR HOOK TO DRAW THE ARRAY HERE
            System.out.println("during: " + Arrays.toString(array));
        }

    }

    public static void merge(int[] numbers, int left, int mid, int right) {
        int[] temp = new int[numbers.length];
        int i, left_end, num_elements, tmp_pos;
        left_end = (mid - 1);
        tmp_pos = left;
        num_elements = (right - left + 1);

        while ((left <= left_end) && (mid <= right)) {
            if (numbers[left] <= numbers[mid])
                temp[tmp_pos++] = numbers[left++];
            else
                temp[tmp_pos++] = numbers[mid++];
        }

        while (left <= left_end)
            temp[tmp_pos++] = numbers[left++];

        while (mid <= right)
            temp[tmp_pos++] = numbers[mid++];

        for (i = 0; i < num_elements; i++){
            numbers[right] = temp[right];
            right--;
        }
    }

}

产生的输出是这样的：

before: [14, 32, 76, 67, 41, 23, 58, 85]
during: [14, 32, 76, 67, 41, 23, 58, 85]
during: [14, 32, 67, 76, 41, 23, 58, 85]
during: [14, 32, 67, 76, 41, 23, 58, 85]
during: [14, 32, 67, 76, 23, 41, 58, 85]
during: [14, 32, 67, 76, 23, 41, 58, 85]
during: [14, 32, 67, 76, 23, 41, 58, 85]
during: [14, 23, 32, 41, 58, 67, 76, 85]
after:  [14, 23, 32, 41, 58, 67, 76, 85]