快速排序算法无法正常工作？

Question

我的快速排序算法没有返回正确的输出。我的输出只是右侧的枢轴元素和左侧小于枢轴元素的元素以及右侧大于枢轴元素的元素。

import java.util.Timer;

class QuickSort {

    public static void quicksort(int[] array, int left, int right) {

        if (left < right) {
            int q = partition(array, left, right);
            quicksort(array, left, q - 1);
            quicksort(array, q + 1, right);
        }
    }

    public static int partition(int[] array, int start, int end) {
        int x = array[end];
        int i = start - 1;
        int temp = 0;
        for (int j = start; j < end - 1; j++) {
            if (array[j] <= x) {
                i++;
                temp = array[j];
                array[j] = array[i];
                array[i] = temp;
            }
        }

        temp = array[end];
        array[end] = array[i + 1];
        array[i + 1] = temp;
        return i + 1;
    }

    public static void main(String[] args) {
        int[] array = { 2, 8, 7, 1, 3, 5, 6, 4 };

        long totalTime = 0;

        System.out.println("Unsorted array");
        for (int i = 0; i < array.length; i++)
            System.out.print(array[i] + " ");
        System.out.println();

        long startTime = System.currentTimeMillis();

        quicksort(array, 0, array.length - 1);

        long endTime = System.currentTimeMillis();
        totalTime = endTime - startTime;

        System.out.println("Total time taken by the algorithm " + totalTime);

        System.out.println("Sorted array");
        for (int i = 0; i < array.length; i++)
            System.out.print(array[i] + " ");
    }
}

请告诉我我的错误并更正我的代码。谢谢。

Answer 1

感谢您查看问题。在这里，是更正。

for(int j = start; j <= end-1; j++){
        if(array[j] <= x){
            i++;
            temp = array[j];
            array[j] = array[i];
            array[i] = temp;
        }

    }

for 循环也会在 end-1 上运行。

快速排序算法无法正常工作？

Quick sort algorithm not working correctly?

java

algorithm

quicksort