public Map Solve(Map map)
{
var cell = map.Cells[0][0];
var dfsStack = new Stack <CellMapPair>();
dfsStack.Push(new CellMapPair(cell, map));
while (dfsStack.Any())
{
var cellMapPair = dfsStack.Pop();
var currentMap = cellMapPair.Map;
var currentCell = cellMapPair.Cell;
if (currentCell.IsSolved)
{
if (currentCell.IsLastCell)
{
return(currentMap);
}
var nextCoordinate = currentCell.Coordinate.GetNextCoordinate();
dfsStack.Push(new CellMapPair(currentMap.Cells[nextCoordinate.Row][nextCoordinate.Column], currentMap));
continue;
}
var candidates = currentCell.Candidates.Any() ? currentCell.Candidates : new List <int> {
1, 2, 3, 4, 5, 6, 7, 8, 9
};
foreach (var candidate in candidates)
{
if (RulesHelper.ViolatesRules(candidate, currentMap, currentCell))
{
continue;
}
var candidateMap = currentMap.Clone();
var candidateCell = currentCell.Clone();
candidateCell.Number = candidate;
candidateMap.Cells[candidateCell.Coordinate.Row][candidateCell.Coordinate.Column] = candidateCell;
if (currentCell.IsLastCell)
{
return(candidateMap);
}
var nextCoordinate = currentCell.Coordinate.GetNextCoordinate();
dfsStack.Push(new CellMapPair(candidateMap.Cells[nextCoordinate.Row][nextCoordinate.Column], candidateMap));
//Console.Clear();
//Console.WriteLine(candidateMap);
//Thread.Sleep(50);
}
}
return(map);
}
private List <int> FindCandidates(Map map, Cell cell)
{
var possibleCandidates = cell.Candidates.Any() ? cell.Candidates : new List <int> {
1, 2, 3, 4, 5, 6, 7, 8, 9
};
var candidates = new List <int>();
foreach (var candidate in possibleCandidates)
{
if (RulesHelper.ViolatesRules(candidate, map, cell))
{
continue;
}
candidates.Add(candidate);
}
return(candidates);
}
