一道随机算法题，C#，在线等哟

Question

如题：
a,b,c,d为变量，A为常量。a,b,c,d的取值在1-36（均可等）之间
表达式为a+b+c+d=A,a!=b,b!=c,c!=d
已知A，现任意随机出一组a,b,c,d

举个栗子：
A=72
a=24,b=14,c=5,d=29
...
不可以是
a=24,b=24,c=18,d=6
...

Answer 1

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Collections;

namespace WindowsFormsApplication1
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}

    private int GetAnswer(int end)
    {
        int num;
        Random random = new Random();
        num = random.Next(end);
        return num;
    }//得到随机数字
    private bool IsSame(int num_1,int num_2,int num_3,int num_4)
    {
        bool rtn = false;
        ArrayList list = new ArrayList();
        list.Add(num_1);
        list.Add(num_2);
        list.Add(num_3);
        list.Add(num_4);

        for (int i = 0; i <= list.Count-1;i++)
        {
            for (int j = i+1; j <= list.Count-1; j++)
            {
                if (list[i] == list[j])
                {
                    rtn = false;
                }
                else
                {
                    rtn = true;
                }
            }
        }
            return rtn;
    }//判断是否有重复

    private void GetRight()
    {
        int anum, bnum, cnum, dnum;

            anum = GetAnswer(Convert.ToInt16(txtA.Text));
            bnum = GetAnswer(Convert.ToInt16(txtA.Text)-anum);
            cnum = GetAnswer(Convert.ToInt16(txtA.Text) - anum-bnum);
            dnum = Convert.ToInt16(txtA.Text) - anum - bnum-cnum;

        if(IsSame(anum,bnum,cnum,dnum))
        {
            lbla.Text = anum.ToString();
            lblb.Text = bnum.ToString();
            lblc.Text = cnum.ToString();
            lbld.Text = dnum.ToString();
        }
        else
        {
            anum = GetAnswer(Convert.ToInt16(txtA.Text));
            bnum = GetAnswer(anum);
            cnum = GetAnswer(bnum);
            dnum = Convert.ToInt16(txtA.Text) - anum - bnum - cnum;
        }


            lbla.Text=anum.ToString();
            lblb.Text=bnum.ToString();
            lblc.Text=cnum.ToString();
            lbld.Text=dnum.ToString();

    }
    private void button1_Click(object sender, EventArgs e)
    {
        if (txtA.Text == "" || txtA.Text == null)
        {
            MessageBox.Show("请输入数据A！");
            txtA.Focus();
        }
        else
        {
            GetRight();
        }
    }
}

}
没有看到“a,b,c,d的取值在1-36（均可等）” 这个条件 其他的 都还好 要是需要原工程加我qq1101559491