第二题：数字方阵，九宫格

1) 阿拉伯数字 1-9 中选择一个数字填入下图中的空白方格内，每格只能填一个数字
2) 当每个格子内都有一个数字后，每行都不可以有重复的数字，每列也不可以有重复的数字
初始界面

运行后结果

      

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

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

            AllData[0, 3] = 7;
            AllData[0, 4] = 2;
            AllData[0, 5] = 8;

            AllData[1, 1] = 9;
            AllData[1, 4] = 5;
            AllData[1, 5] = 1;
            AllData[1, 6] = 6;

            AllData[2, 4] = 6;
            AllData[2, 7] = 8;
            AllData[2, 8] = 2;

            AllData[3, 0] = 3;
            AllData[3, 3] = 8;
            AllData[3, 5] = 2;
            AllData[3, 6] = 7;
            AllData[3, 8] = 4;

            AllData[4, 0] = 1;
            AllData[4, 1] = 7;
            AllData[4, 2] = 4;
            AllData[4, 4] = 3;
            AllData[4, 7] = 2;

            AllData[5, 0] = 2;
            AllData[5, 1] = 8;
            AllData[5, 3] = 5;
            AllData[5, 7] = 3;

            AllData[6, 1] = 1;
            AllData[6, 3] = 3;
            AllData[6, 6] = 2;

            AllData[7, 2] = 7;
            AllData[7, 4] = 4;
            AllData[7, 5] = 6;
            AllData[7, 8] = 5;

            AllData[8, 2] = 6;
            AllData[8, 3] = 1;
            AllData[8, 7] = 4;
            AllData[8, 8] = 9;

            int writelen = 0;
            for (int i = 0; i < 9; i++)
            {
                for (int j = 0; j < 9; j++)
                {
                    if (AllData[i, j] == 0)
                    {
                        writelen++;
                    }
                }
            }
            CanWritePoint = new Apoint[writelen];//可填数字的空白区
            writelen = 0;
            for (int i = 0; i < 9; i++)
            {
                for (int j = 0; j < 9; j++)
                {
                    if (AllData[i, j] == 0)
                    {
                        CanWritePoint[writelen].row = i;
                        CanWritePoint[writelen].column = j;
                        writelen++;
                    }
                }
            }

        }

        int ResultCount = 0;
        static int[,] AllData = new int[9, 9];
        int[] ARow = new int[9] { 1, 2, 3, 4, 5, 6, 7, 8, 9 };
        Apoint[] CanWritePoint;//可以填数字的点


        struct Apoint
        {
            public int row;
            public int column;
        }

        private void button1_Click(object sender, EventArgs e)//GO
        {
            Begain(0);
            ResultNum.Text = ResultCount.ToString();
            ShowResult(AllRe[0]);
        }

        private void Begain(int NowPoint)
        {
            List<int> num = GetPossibleValue(CanWritePoint[NowPoint].row, CanWritePoint[NowPoint].column);
            if (num.Count < 1)//此位置不能填任何数字了
            {
                return;
            }
            
            if (NowPoint == CanWritePoint.Length - 1)//最后一个可填写区了
            {
                AllData[CanWritePoint[NowPoint].row, CanWritePoint[NowPoint].column] = num[0];
                ResultCount++;
                SaveResult();
                AllData[CanWritePoint[NowPoint].row, CanWritePoint[NowPoint].column] = 0;
                return;
            }

            
            List<int>.Enumerator enu = num.GetEnumerator();
            while (enu.MoveNext())
            {
                AllData[CanWritePoint[NowPoint].row, CanWritePoint[NowPoint].column] = enu.Current;
                Begain(NowPoint + 1);
            }
            AllData[CanWritePoint[NowPoint].row, CanWritePoint[NowPoint].column] = 0;
        }

        private List<int> GetPossibleValue(int row, int column)//得到此位置能填的数字
        {
            List<int> re = new List<int>();
            re.AddRange(ARow);
            List<int> temp = new List<int>();
            for (int i = 0; i < 9; i++)
            {
                if (AllData[row, i] != 0)
                {
                    temp.Add(AllData[row, i]);
                }
                if (AllData[i, column] != 0)
                {
                    temp.Add(AllData[i, column]);
                }
            }

            List<int>.Enumerator ie = temp.GetEnumerator();
            while (ie.MoveNext())
            {
                re.Remove(ie.Current);
            }
            return re;
        }

        private List<int[,]> AllRe = new List<int[,]>();//保存所有结果
        private void SaveResult()//保存结果
        {
            int[,] temp = new int[9,9];
            for (int i = 0; i < 9; i++)
            {
                for (int j = 0; j < 9; j++)
                {
                    temp[i, j] = AllData[i, j];
                }
            }
            AllRe.Add(temp);
        }



        //************************************************************
        //下面与算法无关，为了显示结果用的
        int now = 0;
        private void button2_Click(object sender, EventArgs e)//上一个
        {
            if (now == 0)
            {
                MessageBox.Show("已到端点");
                return;
            }
            now--;
            ShowResult(AllRe[now]);
            page.Text = (now+1).ToString();
        }

        private void button3_Click(object sender, EventArgs e)//下一个
        {
            if (now == AllRe.Count - 1)
            {
                MessageBox.Show("已到最后");
                return;
            }
            now++;
            ShowResult(AllRe[now]);
            page.Text = (now + 1).ToString();
        }

        private void ShowResult(int[,] pr)//打印结果
        {
            int row = 0;
            int column = 0;
            foreach (Control co in tlp.Controls)
            {
                if (co.Name.StartsWith("lbl"))
                {
                    Label la = co as Label;
                    row = Convert.ToInt32(co.Name.Substring(3, 1));
                    column = Convert.ToInt32(co.Name.Substring(4));
                    la.Text = pr[row, column].ToString();
                }
            }
        }

    }
}