public static IEnumerable<Grid> GetSolutions(Grid grid)
{
var backtrackingStack = new BacktrackingStack<Grid>();
backtrackingStack.PushAlternatives(new[] { grid.Clone() });
while (true)
{
Grid currentGrid = backtrackingStack.NextAlternative();
if (currentGrid == null)
{
yield break;
}
if (currentGrid.IsUnsolvable)
{
continue;
}
else if (currentGrid.IsSolved)
{
yield return currentGrid;
}
backtrackingStack.PushAlternatives(currentGrid.GetAlternatives());
}
}
/// <summary>
/// Initializes a new Sudoku <see cref="Puzzle"/> instance from a string.
/// </summary>
public Puzzle(string name, string gridString)
{
Name = name;
GridString = gridString;
Grid = new Grid();
Grid.Load(GridString);
}
public void Test25X25Grids()
{
string[] inputGrids = {
"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"
};
string[] solvedGrids = {
"ETLMRVUOAKSNWGPDHBCQFJIYXOFPNQHGRYIKCEJBWVSXUAMTLDDABHISLMCQYUXTOJFREGNWPVKUVXWSNDJEPMFIRAYKOLTCHGQBKYCGJXFTBWQDHVLANIMPESOURADJLVQIUGBHOYSWEXTRMKFCPNXNSEODVKTJCRBPQUGLFAMIYWHYKFTCPRAHMJENUGODVIWSQXBLRIWQHFOYNXLAMDVPBCSKTGUEJPMGBUWCSLEIKTFXQYHNJORADVMORIEBKFUNTQDXSCJPYHLAVGWFJUPWOMGDTAYLHEIRQVBXCNKSGCQKYAXLIVBJRWUTONDSHPFMEHLTSDEPCWRNMVOKXAUGFYBQJINBAVXJHQSYFPGCIKMEWLUDRTOLQVCGMSEPURWFKHBIYAXDOJNTBRDAMINWFCOTJLYSQKUVPEHXGTSIXPKJDVOUGQAMNLWHERYBCFJHOUNYQBRLXISECFPGTDVKWAMWEKYFTAHXGVBPNDRCMJOQLSIUVWEFLUBPKADHCYRGTXOIJNMSQQGHOALTIJFPXUBNMSDKCWVERYCUMJKGYNOSELAITVWFQRBXDHPIXYDBREVQHWSOMJLUAPNGTKFCSPNRTCWXMDGVKQFHEJBYIULOA"
};
for (int i = 0; i < inputGrids.Length; i++)
{
Grid grid = new Grid(inputGrids[i]);
bool solved = grid.Solve();
Assert.True(solved);
Assert.AreEqual(grid.GridString, solvedGrids[i]);
}
}
public void Test16X16Grids()
{
string[] inputGrids = {
"JP00000000LA000B000E0D00KBM0F0J00NK0BCL0J0000A0G00F0I0MOG00H0L00GKJB0000000F00LDA0P0000LBKE0000N000000A00H0000I00I0000N0ADJ00KG00CE00AKH0M0000N00J0000P00N000000K0000NDIH0000M0FMA00C0000000LEHK00A0N00PMI0D0F00I0L0000E0FAK0GD00F0N0OIC00B0J000P000HL00000000BA"
,
"0BN000PD000A00E000I00J0A00000D000000MF000N00OL0PFEJ0HB000L000A0GI0EDA00B0000L0G00000K00M0C00000A0000P000MJOIN0D0J00K0DHO0000E0M00K0A0000JGD0C00F0G0BNPFJ000K0000P00000A0L00N00000D0J0000O00BPE0KK0L000N000MG0IFBH0GI00K000NJ000000D00000K0B00H000F00L000IH000NA0"
};
string[] solvedGrids = {
"JPIMKGENFOLAHDCBLGCEPDHAKBMIFNJOONKHBCLFJEDPIAMGBDFAIJMOGCNHKLEPGKJBOECMNPIFAHLDAHPDGIJLBKECMOFNNEMFDPAKOHGLBJICCIOLFHNBADJMPKGEDCEPLAKHIMFOGBNJFJHOMBPGLNKEDCAIKLBGENDIHACJOMPFMANICFOJDGPBLEHKEBAJNKGPMIHDCFOLIOLCJMBEPFAKNGDHHFDNAOICELBGJPKMPMGKHLFDCJONEIBA"
,
"GBNLCKPDHOIAFJEMCPIOEJLAGBFMHDKNDAKHMFGIENJCOLBPFEJMHBONPLKDIACGIMEDACJBNKPHLFGOOLPFKNIMDCGEJBHABHAGPLEFMJOINKDCJNCKGDHOBALFEPMINKHAOEBLJGDPCMIFEGMBNPFJCIHKAOLDPIOCDMAKLFENBGJHLDFJIHCGOMABPENKKCLPJONHAEMGDIFBHOGIBAKEFDNJMCPLAJDNFIMCKPBLGHOEMFBELGDPIHCOKNAJ"
};
for (int i = 0; i < inputGrids.Length; i++)
{
Grid grid = new Grid(inputGrids[i]);
bool solved = grid.Solve();
Assert.True(solved);
Assert.AreEqual(grid.GridString, solvedGrids[i]);
}
}
public void Test9X9Grids()
{
string[] inputGrids = {
"530070000600195000098000060800060003400803001700020006060000280000419005000080079"
,
"004050900005800104000100000040002003600405008100900050000001000409007500001020700"
,
"000004270600085000007120000002000090001306700040000300000079100000450002054600000"
,
"000003072005004003000280009710000600804000901002000047900012000600500200250900000"
};
string[] solvedGrids = {
"534678912672195348198342567859761423426853791713924856961537284287419635345286179"
,
"814253976265879134973146825548712693697435218132968457786591342429387561351624789"
,
"815964273623785419497123568362547891581396724749218356236879145978451632154632987"
,
"489653172125794863376281459713429685864375921592168347947812536631547298258936714"
};
for (int i = 0; i < inputGrids.Length; i++)
{
Grid grid = new Grid(inputGrids[i]);
bool solved = grid.Solve();
Assert.True(solved);
Assert.AreEqual(grid.GridString, solvedGrids[i]);
}
}
public Column(int id, Grid grid)
: base(id, grid)
{
}
public Box(int id, Grid grid)
: base(id, grid)
{
}
public Segment(int id, Grid grid)
{
Id = id;
Grid = grid;
}
public Row(int id, Grid grid)
: base(id, grid)
{
}
/// <summary>
/// Initializes a new Sudoku <see cref="Puzzle"/> instance from a grid.
/// </summary>
public Puzzle(string name, Grid grid)
{
Name = name;
Grid = grid;
}
/// <summary>
/// Guess a value by forking new puzzle instances.
/// </summary>
private bool Guess()
{
int leastPossibilities = 10;
int bestCandidate = -1;
for (int ci=0; ci<81; ci++) {
Cell cell = Grid.Cells[ci];
if (cell.Value == 0 && cell.Possibilities.Count < leastPossibilities) {
leastPossibilities = cell.Possibilities.Count;
bestCandidate = ci;
}
}
if (bestCandidate > -1) {
foreach(int p in Grid.Cells[bestCandidate].Possibilities) {
Grid newGrid = new Grid();
newGrid.LoadState(Grid.SaveState());
newGrid.Cells[bestCandidate].Value = p;
Puzzle puzzle = new Puzzle(Name, newGrid);
puzzle.SaveStateHistory = SaveStateHistory;
puzzle.Solve("Guess");
if(puzzle.Solved) {
Grid.LoadState(newGrid.SaveState());
State.Concat(puzzle.State);
Solved = true;
return true;
}
}
}
return false;
}
static void DrawGrid(Grid grid)
{
Console.ForegroundColor = ConsoleColor.Gray;
int subgridWidth = (int) Math.Sqrt(grid.SideLength);
Console.Write("╔");
for (int i = 0; i < subgridWidth -1;i++)
Console.Write(new string('═', subgridWidth * 2 - 1) + "╦");
Console.WriteLine(new string('═', subgridWidth*2 - 1) + "╗");
//Console.WriteLine("╔═════╦═════╦═════╗");
for (int row = 0; row < grid.SideLength; row++)
{
for (int column = 0; column < grid.SideLength; column++)
{
Cell cell = grid.Cells[row, column];
if (column % subgridWidth == 0)
{
Console.ForegroundColor = ConsoleColor.Gray;
Console.Write("║");
if (cell.Value == Cell.CellValue.None)
{
Console.ForegroundColor = ConsoleColor.Red;
Console.Write("░");
}
else
{
if (grid.SolvedCells.Contains(cell))
Console.ForegroundColor = ConsoleColor.Green;
else if (grid.PresolvedCells.Contains(cell))
Console.ForegroundColor = ConsoleColor.Gray;
if (grid.SideLength > 9 && cell.Value != Cell.CellValue.None)
Console.Write((char)('@' + cell.Value));
else
Console.Write((int) cell.Value);
}
}
else
{
Console.ForegroundColor = ConsoleColor.Gray;
Console.Write("│");
if (cell.Value == Cell.CellValue.None)
{
Console.ForegroundColor = ConsoleColor.Red;
Console.Write("░");
}
else
{
if (grid.SolvedCells.Contains(cell))
Console.ForegroundColor = ConsoleColor.Green;
else if (grid.PresolvedCells.Contains(cell))
Console.ForegroundColor = ConsoleColor.Gray;
if (grid.SideLength > 9)
Console.Write((char)('@' + cell.Value));
else
Console.Write((int)cell.Value);
}
}
}
Console.ForegroundColor = ConsoleColor.Gray;
Console.WriteLine("║");
if ((row + 1) % subgridWidth == 0 && row < grid.SideLength - 1)
{
Console.Write("╠");
for (int i = 0; i < subgridWidth - 1; i++)
Console.Write(new string('═', subgridWidth * 2 - 1) + "╬");
Console.WriteLine(new string('═', subgridWidth * 2 - 1) + "╣");
}
else if (row != grid.SideLength -1)
{
Console.Write("╠");
for (int i = 0; i < subgridWidth ; i++)
{
for (int j = 0; j < subgridWidth -1;j++)
{
Console.Write("─┼");
}
Console.Write("-║");
}
Console.WriteLine();
//Console.WriteLine("╠─┼─┼─║─┼─┼─║─┼─┼─╣");
}
}
Console.Write("╚");
for (int i = 0; i < subgridWidth - 1; i++)
Console.Write(new string('═', subgridWidth * 2 - 1) + "╩");
Console.WriteLine(new string('═', subgridWidth * 2 - 1) + "╝");
Console.WriteLine(grid.SolvedCells.Count + " cells solved.");
Console.WriteLine(grid.GridString);
Console.ForegroundColor = ConsoleColor.Gray;
}
static void Main(string[] args)
{
Console.WindowHeight = 50;
Console.WindowWidth = 85;
Console.WriteLine(
"A gridstring looks like 530070000600195000098000060800060003400803001700020006060000280000419005000080079");
Console.WriteLine("Substitute 0 for empty fields and do not use line-breaks.");
while (true)
{
Console.Write("Enter a gridstring: ");
string inputString = Console.ReadLine();
if (inputString != null && inputString.Length < 5)
{
switch (inputString)
{
case "1":
inputString = TestString1;
break;
case "2":
inputString = TestString2;
break;
case "3":
inputString = TestString3;
break;
case "4":
inputString = TestString4;
break;
case "5":
inputString = TestString5;
break;
case "6":
inputString = TestString6;
break;
case "7":
inputString = TestString7;
break;
case "8":
inputString = TestString8;
break;
default:
Console.WriteLine("Invalid Gridstring.");
break;
}
}
try
{
Grid grid = new Grid(inputString);
if (grid.Cells == null)
continue;
Console.ForegroundColor = ConsoleColor.Blue;
Console.WriteLine("Original");
DrawGrid(grid);
if (grid.Solve())
{
Console.ForegroundColor = ConsoleColor.Green;
Console.WriteLine("Solved");
DrawGrid(grid);
}
else
{
Console.ForegroundColor = ConsoleColor.Red;
Console.WriteLine("Unsolved");
DrawGrid(grid);
}
}
catch (Exception e)
{
Console.WriteLine(e.Message);
}
}
}
