Java开发网 - 数组排序问题 ?

Topic: 数组排序问题 ?

1.数组排序问题 ?	Copy to clipboard
Posted by: heartache Posted on: 2006-03-22 20:40 我的代码 (用记事本编辑的): public class sort { public static void main(String[] args) { int[] a={12,8,47,51,91,82,100,84,72,19}; System.out.println(java.util.Arrays.sort(a[])); } } 运行报错, 请问是怎么回事 ? : { Please don't use BMP, 100KB BMP --> 3KB GIF --why }

2.Re:数组排序问题 ? [Re: heartache]

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Posted by: zcjl
Posted on: 2006-03-23 00:47

import java.util.Arrays;
import org.apache.commons.lang.ArrayUtils;

public class TestSort {

    public static void main(String[] args) {
        int[] a = { 12, 8, 47, 51, 91, 82, 100, 84, 72, 19 };
        System.out.println(ArrayUtils.toString(a));
        Arrays.sort(a);
        System.out.println(ArrayUtils.toString(a));
    }

}

代码需要jakarta-commons-lang-2.0.jar

3.Re:数组排序问题 ? 新问题来了！ [Re: heartache]	Copy to clipboard
Posted by: heartache Posted on: 2006-03-23 09:36 结果又有更多错误！ { converted 422KB BMP to this 6KB GIF with the simple Paint program; unnecessary stuff at the bottom right had been removed. Actually, in this case, you should just cut-n-paste the contents from the Command Prompt window, instead of using an image -- why }

4.Re:数组排序问题 ? [Re: heartache]	Copy to clipboard
Posted by: heartache Posted on: 2006-03-23 09:40 jakarta-commons-lang-2.0.jar 　ＪＤＫ里面好象没有看到这个东西呢　？

5.Re:数组排序问题 ? [Re: heartache]	Copy to clipboard
Posted by: jackyangf Posted on: 2006-03-23 10:11 ........ sort 没有返回值，你怎么print ? 用一个方法最少的看看说明吧？

6.Re:数组排序问题 ? [Re: heartache]	Copy to clipboard
Posted by: zcjl Posted on: 2006-03-23 11:13 heartache wrote: jakarta-commons-lang-2.0.jar 　ＪＤＫ里面好象没有看到这个东西呢　？ JDK里面本来就没有啊不过你google一下就会找到了或者去这里： http://www.apache.org/dist/jakarta/commons/lang/binaries/

7.Re:数组排序问题 ? [Re: zcjl]

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Posted by: why
Posted on: 2006-03-23 18:30

zcjl wrote:

import java.util.Arrays;
import org.apache.commons.lang.ArrayUtils;

public class TestSort {

    public static void main(String[] args) {
        int[] a = { 12, 8, 47, 51, 91, 82, 100, 84, 72, 19 };
        System.out.println(ArrayUtils.toString(a));
        Arrays.sort(a);
        System.out.println(ArrayUtils.toString(a));
    }

}

代码需要jakarta-commons-lang-2.0.jar

heartache: as you may noticed, ArrayUtils.toString(a) is used for printing the array.
java.util.Arrays.sort(a[])) is wrong, should be java.util.Arrays.sort(a)), as in zcjl's code.

8.Re:数组排序问题 ? [Re: heartache]	Copy to clipboard
Posted by: phoenix451 Posted on: 2006-03-24 08:45 出错的原因是java.util.Arrays.sort(a)返回的是ivoid类型数据，把程序改成如下就可以了： public class sort { public static void main(String[] args) { int[] a={12,8,47,51,91,82,100,84,72,19}; java.util.Arrays.sort(a); for(int i=0;i<a.length;i++) { System.out.println(a[i]); } } } check "Disable Smileys"

9.Re:数组排序问题 ? [Re: heartache]	Copy to clipboard
Posted by: phoenix451 Posted on: 2006-03-24 09:04 不知道怎么回事，（）内部加a全部变成了一个脸，出错的原因是java.util.Arrays.sort(a[])) , 它应该是java.util.Arrays.sort

10.Re:数组排序问题 ? [Re: heartache]	Copy to clipboard
Posted by: phoenix451 Posted on: 2006-03-24 09:05 Post is deleted

11.Re:数组排序问题 ? [Re: phoenix451]	Copy to clipboard
Posted by: zcjl Posted on: 2006-03-24 09:05 phoenix451 wrote: java.util.Arrays.sort(a))

12.Re:数组排序问题 ? [Re: heartache]

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Posted by: suntao19830709
Posted on: 2006-03-24 09:57

给你一个我写的快速排序的算法


/**
     * 快速排序
     * @param num
     * @param begin
     * @param end
     */
    public void doQuickOrder(int[] num, int begin, int end) {
        // 计算传入的无序列的长度
        int length = end + 1 - begin;
        if (length > 1) {
            // 设置无序列的第一个元素为中间参考元素
            int middle = num[begin];

            // ----将最终结果按照 小序列+中间元素+大序列(包括等于) 的顺序合并begin//
            int minNum = 0;
            int temp = 0;
            // 将小于中间元素的元素往靠左的位置排,中间元素位置不变
            for (int i = begin + 1; i < end + 1; i++) {
                if (num[i] < middle) {
                    minNum++;
                    if (i != begin + minNum) {
                        temp = num[begin + minNum];
                        num[begin + minNum] = num[i];
                        num[i] = temp;
                    }
                }
            }
            // 交换中间元素位置
            if (minNum != 0) {
                num[begin] = num[begin + minNum];
                num[begin + minNum] = middle;
            }
            // ----将最终结果按照 小序列+中间元素+大序列(包括等于) 的顺序合并end//

            // ----对小序列和大序列分别递归执行快速排序begin//
            doQuickOrder(num, begin, begin + minNum - 1);
            doQuickOrder(num, begin + minNum + 1, end);
            // ----对小序列和大序列分别递归执行快速排序end//
        }
    }

    /**
     * 快速排序
     * @param num
     */
    public void doQuickOrder(int[] num) {
        doQuickOrder(num, 0, num.length - 1);
    }