private void SolveRecursive(IProblem problem, Board initial, Board board, IAssignmentCollection assignments)
{
var availableAssignments = problem.GetDomains(board).ToList();
// if there's no more assignments the game is done, save, then go back up the chain
if (availableAssignments.Count == 0)
{
solutions.Add(new Solution(initial, assignments));
return;
}
foreach (var assignment in availableAssignments)
{
// keep a list of visited nodes. if we've seen this
// before then skip it, no need to explore it again
string hashCode = assignment.Board.ToString(false);
if (visitedNodes.Contains(hashCode))
continue;
else
visitedNodes.Add(hashCode);
// add assignment to previous lsit
var newAssignments = assignments.Clone();
newAssignments.Add(assignment);
// recurse down
recursionLevel++;
SolveRecursive(problem, initial, assignment.Board, newAssignments);
recursionLevel--;
}
}
public Solution(Board initialState, IEnumerable<Assignment> assignments)
{
Check.Require(initialState != null, "initialState is a required argument.");
Check.Require(assignments != null, "assignments is a required argument.");
InitialState = initialState;
Assignments = new ReadOnlyCollection<Assignment>(assignments.ToList());
FinalState = Assignments.Last().Board;
PegCount = FinalState.PegCount;
Depth = Assignments.Count;
}
public virtual IEnumerable<Assignment> GetDomains(Board board)
{
var assignments = new List<Assignment>();
var pegSpaces = board.GetSpacesWithPegs();
foreach (var peg in pegSpaces)
{
var jumps = GetAvailableJumps(board, peg);
if (jumps.Count > 0)
assignments.AddRange(jumps.Select(jump =>
new Assignment(board.ExecuteJump(jump), jump)));
}
return assignments;
}
private List<Jump> GetAvailableJumps(Board board, Coordinate peg)
{
List<Jump> jumps = new List<Jump>();
// check each direction
for (int i = 0; i < xs.Length; i++)
{
var jumped = new Coordinate(peg.X + (xs[i] * 1), peg.Y + (ys[i] * 1));
var target = new Coordinate(peg.X + (xs[i] * 2), peg.Y + (ys[i] * 2));
// check that the next coord over and the one after that exist
// and that next has a peg to jump and the one after is empty
if (board.ContainsCoordinate(jumped) &&
board.ContainsCoordinate(target) &&
board[jumped].HasPeg == true &&
board[target].HasPeg == false)
jumps.Add(new Jump(peg, jumped, target));
}
return jumps;
}
/// <summary>
/// Returns true if the boards have the same positions
/// and peg value. Otherwise false.
/// </summary>
/// <param name="board">The board to compare to this one.</param>
/// <returns>True if equivalent, otherwise false.</returns>
public bool IsEquivalent(Board board)
{
Check.Require(board != null, "board is a required argument and cannot be null.");
if (this.Rank != board.Rank)
return false;
for (int i = 0; i < spaces.Length; i++)
{
if (spaces[i] != board.spaces[i] ||
spaces[i].HasPeg != board.spaces[i].HasPeg)
return false;
}
return true;
}
