using System;
using System.Collections.Generic;
using System.Text;
namespace SokoSolve.Common.Structures.Evaluation{
/// <summary>
/// High-speed, optimised, breadth-first (shallowest node first) Eval Strategy iterator
/// </summary>
/// <typeparam name="T"></typeparam>
public class BreadthFirstItterator<T> : BaseItterator<T>
{
public BreadthFirstItterator(GetDepthDelegate getDepth) : base(getDepth)
{
evaluationList = new PriorityWorkQueue<INode<T>>(CompareDepth);
}
private int CompareDepth(INode<T> lhs, INode<T> rhs)
{
return GetDepth(lhs).CompareTo(GetDepth(rhs));
}
/// <summary>
/// Get the next node to evaluate, based on depth-first.
/// </summary>
/// <returns></returns>
public override INode<T> GetNext(out EvalStatus Status)
{
if (evaluationList.Count == 0)
{
exitStatus = EvalStatus.CompleteNoSolution;
Status = exitStatus;
return null;
}
INode<T> next = evaluationList.GetBest();
if (CheckExitConditions(next))
{
exitStatus = EvalStatus.ExitIncomplete;
Status = exitStatus;
return null;
}
Status = exitStatus;
return next;
}
/// <summary>
/// Add another node to evaluate
/// </summary>
/// <param name="NewEvalNode"></param>
public override void Add(INode<T> NewEvalNode)
{
evaluationList.Add(NewEvalNode);
}
/// <summary>
/// Return a copy of the evaluation list
/// </summary>
/// <returns></returns>
public override List<INode<T>> GetEvalList()
{
throw new NotImplementedException();
}
public override void Clear()
{
evaluationList.Clear();
}
/// <summary>
/// Remove a node (it has been evaluated)
/// </summary>
/// <param name="EvalNode"></param>
public override void Remove(INode<T> EvalNode)
{
evaluationList.Remove(EvalNode);
}
public override string ToString()
{
return string.Format("{0} EvalList:{1} LastStatus:{2} Itt:{3} Depth:{4}",
this.GetType().Name, evaluationList.Count, exitStatus, currentItteration, currentMaxDepth);
}
protected PriorityWorkQueue<INode<T>> evaluationList;
}
}
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