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，左侧的元素小于枢轴元素，右侧的元素大于枢轴元素。

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

感谢您查看该问题。在这里，是纠正。

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

    }

for循环也将在end-1上运行。

快速排序算法无法正常工作？

1 个答案: