C# WPF 数独求解器

原来写过的数独算法，套了个WPF的框，方便数独输入和输出。

<hc:GlowWindow x:Class="WPFSudokuSolver.Views.MainWindow"
               xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
               xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
               xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
               xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
               xmlns:vm="clr-namespace:WPFSudokuSolver.ViewModels"
               xmlns:hc="https://handyorg.github.io/handycontrol"
               d:DataContext="{d:DesignInstance Type=vm:MainViewModel}"
               mc:Ignorable="d"
               Title="Sudoku Puzzle" Height="480" Width="800" Background="White"
               FontFamily="JetBrains Mono" ResizeMode="NoResize"
               FontSize="{StaticResource TextFontSize}">
    <Window.Resources>
    </Window.Resources>
    <hc:SimplePanel>
        <ScrollViewer x:Name="scrollViewer" VerticalScrollBarVisibility="Auto">
            <Grid>
                <Grid.RowDefinitions>
                    <RowDefinition Height="*" />
                    <RowDefinition Height="8*" />
                </Grid.RowDefinitions>
                <Grid.ColumnDefinitions>
                    <ColumnDefinition />
                    <ColumnDefinition />
                </Grid.ColumnDefinitions>
                <TextBlock Grid.Row="0" Grid.Column="0" Text="Sudoku Puzzle Solver"
                           Style="{StaticResource TextBlockDefaultPrimary}" FontSize="20" HorizontalAlignment="Left"
                           Margin="10" />
                <Button Grid.Row="0" Grid.Column="0" Content="Solve" Style="{StaticResource ButtonPrimary}" Margin="10"
                        HorizontalAlignment="Right"
                        Command="{Binding SolveCommand}" />
                <WrapPanel Grid.Row="0" Grid.Column="1" VerticalAlignment="Center">
                    <TextBox hc:InfoElement.Title="Steps:" hc:InfoElement.TitlePlacement="Left" Margin="10, 0"
                             Style="{StaticResource TextBoxExtend}" IsReadOnly="True" VerticalAlignment="Center"
                             FontSize="12" Foreground="{StaticResource PrimaryBrush}" Width="250"
                             Text="{Binding Steps}" />
                </WrapPanel>

                <StackPanel Grid.Row="1" Grid.Column="0">
                    <TextBlock Text="Original Matrix" Style="{StaticResource TextBlockDefaultInfo}" />
                    <ItemsControl ItemsSource="{Binding OriginalBlocks}" Margin="10">
                        <ItemsControl.ItemsPanel>
                            <ItemsPanelTemplate>
                                <Canvas />
                            </ItemsPanelTemplate>
                        </ItemsControl.ItemsPanel>
                        <ItemsControl.ItemContainerStyle>
                            <Style TargetType="ContentPresenter">
                                <Setter Property="Canvas.Left" Value="{Binding XPosActual}" />
                                <Setter Property="Canvas.Top" Value="{Binding YPosActual}" />
                            </Style>
                        </ItemsControl.ItemContainerStyle>
                        <ItemsControl.ItemTemplate>
                            <DataTemplate>
                                <Border BorderBrush="DarkGray" BorderThickness="1" Width="40" Height="40">
                                    <TextBox Text="{Binding BlockType, Mode=TwoWay}"
                                             HorizontalContentAlignment="Center" VerticalContentAlignment="Center"
                                             FontSize="20" />
                                </Border>
                            </DataTemplate>
                        </ItemsControl.ItemTemplate>
                    </ItemsControl>
                </StackPanel>
                <StackPanel Grid.Row="1" Grid.Column="1">
                    <TextBlock Text="Solution Matrix" Style="{StaticResource TextBlockDefaultSuccess}" />
                    <ItemsControl ItemsSource="{Binding SolvedBlocks}" Margin="10">
                        <ItemsControl.ItemsPanel>
                            <ItemsPanelTemplate>
                                <Canvas />
                            </ItemsPanelTemplate>
                        </ItemsControl.ItemsPanel>
                        <ItemsControl.ItemContainerStyle>
                            <Style TargetType="ContentPresenter">
                                <Setter Property="Canvas.Left" Value="{Binding XPosActual}" />
                                <Setter Property="Canvas.Top" Value="{Binding YPosActual}" />
                            </Style>
                        </ItemsControl.ItemContainerStyle>
                        <ItemsControl.ItemTemplate>
                            <DataTemplate>
                                <Border BorderBrush="DarkGray" BorderThickness="1" Width="40" Height="40">
                                    <TextBox Text="{Binding BlockType}" IsReadOnly="True"
                                             HorizontalContentAlignment="Center" VerticalContentAlignment="Center"
                                             FontSize="20" />
                                </Border>
                            </DataTemplate>
                        </ItemsControl.ItemTemplate>
                    </ItemsControl>
                </StackPanel>
            </Grid>
        </ScrollViewer>
    </hc:SimplePanel>
</hc:GlowWindow>

using System.ComponentModel;
using CommunityToolkit.Mvvm.ComponentModel;

namespace WPFSudokuSolver.Models;

public partial class BlockModel : ObservableObject
{
    [ObservableProperty] private int _blockSize;
    [ObservableProperty] private string _blockType;
    [ObservableProperty] private int _xPos;

    [ObservableProperty] private int _xPosActual;
    [ObservableProperty] private int _yPos;
    [ObservableProperty] private int _yPosActual;

    public BlockModel()
    {
    }

    public BlockModel(string _type, int _x, int _y, int _blockSize = 40)
    {
        BlockType = _type;
        BlockSize = _blockSize;
        XPos = _x;
        YPos = _y;
    }

    protected override void OnPropertyChanged(PropertyChangedEventArgs e)
    {
        base.OnPropertyChanged(e);
        switch (e.PropertyName)
        {
            case "XPos":
                XPosActual = XPos * BlockSize;
                break;
            case "YPos":
                YPosActual = YPos * BlockSize;
                break;
        }
    }
}

using System.ComponentModel;
using System.Threading.Tasks;
using CommunityToolkit.Mvvm.ComponentModel;
using CommunityToolkit.Mvvm.Input;
using WPFSudokuSolver.Models;

namespace WPFSudokuSolver.ViewModels;

public partial class MainViewModel : ObservableObject
{
    [ObservableProperty] private int _blockSize;
    [ObservableProperty] private BindingList<BlockModel> _originalBlocks;
    [ObservableProperty] private BindingList<BlockModel> _solvedBlocks;
    [ObservableProperty] private int _steps;

    private readonly char[,] matrix;

    public MainViewModel()
    {
        Steps = 0;
        matrix = new char[9, 9];
        BlockSize = 40;
        OriginalBlocks = new BindingList<BlockModel>();
        SolvedBlocks = new BindingList<BlockModel>();
        for (var i = 0; i < 9; i++)
        for (var j = 0; j < 9; j++)
        {
            var oblock = new BlockModel(string.Empty, i, j, BlockSize);
            var sblock = new BlockModel(string.Empty, i, j, BlockSize);
            OriginalBlocks.Add(oblock);
            SolvedBlocks.Add(sblock);
        }
    }

    [RelayCommand]
    public async Task SolveAsync()
    {
        for (var i = 0; i < 9; i++)
        for (var j = 0; j < 9; j++)
            foreach (var oblock in OriginalBlocks)
                if (oblock.XPos == i && oblock.YPos == j)
                    matrix[i, j] = oblock.BlockType.Length > 0 ? oblock.BlockType[0] : '.';
        await Task.Run(() =>
        {
            var solver = new SudokuSolver();
            solver.Solve(matrix);
            Steps = solver.steps;
        });

        for (var i = 0; i < 9; i++)
        for (var j = 0; j < 9; j++)
            foreach (var sblock in SolvedBlocks)
                if (sblock.XPos == i && sblock.YPos == j)
                    sblock.BlockType = matrix[i, j].ToString();
    }
}

internal class SudokuSolver
{
    public int steps;

    public bool Solve(char[,] board)
    {
        for (var row = 0; row < 9; row++)
        for (var col = 0; col < 9; col++)
            if (board[row, col] == '.')
            {
                for (var num = '1'; num <= '9'; num++)
                {
                    steps++;
                    if (IsValid(board, row, col, num))
                    {
                        board[row, col] = num;

                        if (Solve(board))
                            return true;

                        board[row, col] = '.'; // 回溯
                    }
                }

                return false; // 当前情况无解
            }

        return true; // 数独已解答
    }

    private bool IsValid(char[,] board, int row, int col, char num)
    {
        for (var i = 0; i < 9; i++)
        {
            if (board[i, col] != '.' && board[i, col] == num)
                return false;

            if (board[row, i] != '.' && board[row, i] == num)
                return false;

            var boxRow = 3 * (row / 3) + i / 3;
            var boxCol = 3 * (col / 3) + i % 3;

            if (board[boxRow, boxCol] != '.' && board[boxRow, boxCol] == num)
                return false;
        }

        return true;
    }
}