我想到的也是最后这个办法，不过这个方法近似于穷举，要知道所有的情况才能这样做，不知道所有的情况就没办法了。

运行时候结果为空！    么原因啊？

我做做的是单元加程序．．你要自己输入的数据．．然后对你的数据进行分解．．．

复制内容到剪贴板

代码:

package wwwww;

public class Untitled1 {
    static int sum = 0;
    static int count = 0;
    public static void main(String[] args) {
        final int result = 10;
        int a[] = {1, 2, 3, 4, 5, 6, 7, 8, 9};
        for (int i = 0; i < a.length; i++) {
            for (int j = 1; j < a.length; j++) {
                if ((a[i] + a[j]) == result) {
                    if (a[i] != a[j]) {
                        if (a[i] < a[j]) {
                            System.out.println("result=" + a[i] + "+" + a[j]);
                        }
                    }
                }
                for (int m = 2; m < a.length; m++) {
                    if ((a[i] + a[j] + a[m]) == result) {
                        if (a[i] < a[j]) {
                            if (a[j] < a[m]) {
                                if (a[i] != a[j]) {
                                    if (a[i] != a[m]) {
                                        if (a[j] != a[m]) {
                                            System.out.println("result=" + a[i] +
                                                    "+" +
                                                    a[j] + "+" +
                                                    a[m]);
                                        }
                                    }
                                }
                            }
                        }
                    }
                    for (int n = 3; n < a.length; n++) {
                        if ((a[i] + a[j] + a[m] + a[n]) == result) {
                            System.out.println("result=" + a[i] +
                                               "+" + a[j] +
                                               "+" + a[m] +
                                               "+" + a[n]);
                        }

                    }
                }
            }

        }
    }
}

建议你用递归做．．．背包法．．从九开始找．．直到指针下降到１

import java.io.*;
class demo{
private int a[]={0,1,2,3,4,5,6,7,8,9};
public  boolean knap(int s,int n)
{
   if(s<0||(s>0&&n<1))
   return false;
   if(s==0)
   return true;
   if(knap(s-a[n],n))
   {  
     System.out.print(a[n]);
     return true;
       }
       
     knap(s-a[n],n-1);
    return knap(s,n-1);   
}

public static void main(String []arg)
{
int m;
InputStreamReader isr=new InputStreamReader(System.in);
BufferedReader br=new BufferedReader(isr);
String s;
demo d=new demo();
try{
    s=br.readLine();
    m=Integer.parseInt(s);
  for(int i=9;i>=0;i--)
    {
        if(d.knap(m,i))
        System.out.println();
        }
}catch(Exception e)
{
    System.out.println(e.toString());
    }

}
}

[ 本帖最后由 sunkaidong 于 2008-5-13 12:43 编辑 ]

你改该就可以了