新人求教C#代码

Question

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;namespace C2CsharpCon
{
    class Program
    {
        static void Main(string[] args)
        {
            int n, i, box_count, box_volume;
            HNODE box_h = new HNODE(), box_t = new HNODE(), box_u = new HNODE(), j = new HNODE();
            ELE p = new ELE(), q = new ELE();
            Console.WriteLine("输入箱子容积");
            box_volume = int.Parse(Console.ReadLine());
            Console.WriteLine("输入物品种数");
            n = int.Parse(Console.ReadLine());
            int[] a = new int[n];
            Console.WriteLine("请按体积从大到小顺序输入各物品的体积：");
            for (i = 0; i < n; i++) a[i] = int.Parse(Console.ReadLine());
            //box_h=box_t= null;
            box_count = 0;
            for (i = 0; i < n; i++)
            {
                p.vno = i;
                for (j= box_h; j != null; j = j.next)
                {
                    if (j.remainder >= a[i]) break;
                    if (j == null)
                    {
                        j.remainder = box_volume - a[i];
                        j.head = null;
                        if (box_h == null) box_h = box_t = j;
                        else box_t = box_t.next = j;
                        j.next = null;
                        box_count++;
                    }
                    else
                    {
                        j.remainder -= a[i];
                    }
                }               
                for (q = j.head; q != null && q.link != null; q = q.link) ;
                if (q == null)
                {
                    p.link = j.head;
                    j.head = p;
                }
                else
                {
                   p.link = null;
                    q.link = p;
                }
            }
            Console.WriteLine("共使用了箱子"+ box_count);
            Console.WriteLine("各箱子装物品情况如下：");            for (j = box_h, i = 1; j != null; j = j.next, i++)
            {
                Console.WriteLine("第只箱子；"+i);
                Console.WriteLine("还剩余容积，所装物品有；"  +j.remainder);
                for (p = j.head; p != null; p = p.link)
                    Console.WriteLine("%4d"+p.vno + 1);
                Console.ReadLine();
            }
        }
    }    class HNODE
    {
        public int remainder;
        public ELE head;
        public HNODE next;
    }
    class ELE
    {
        public int vno;
        public ELE link;
    }}
贪婪算法的装箱求解，可是编译出错，求大神帮忙

Answer 1

测试了你的例子，能编译通过，但是输入数量和体积后会报错，j为null

Answer 2

你上面的循环
    for (j= box_h; j != null; j = j.next)
决定了j肯定是null，所以循环完毕后把j还指向头地址

Answer 3

for (j= box_h; j != null; j = j.next)4楼正解！建议楼主还是看看那个算法的思想，不要随便把C写成C#，或者先了解下这两张语言的不同之处。PS:我也不懂贪婪算法

Answer 4

循环前用个临时变量记住j.head
var temp=j.head;
for (j= box_h; j != null; j = j.next)
{...
}j=temp;
for(...)