/// <summary>
/// DFS search on searchable.
/// </summary>
/// <param name="searchable">The searchable to search.</param>
/// <returns>the search States Tree</returns>
private TreeSearchResult <T> DFSSearch(ISearchable <T> searchable)
{
TreeSearchResult <T> resultTree = new TreeSearchResult <T>(searchable.GetInitialState());
// closed list - HashSet
HashSet <State <T> > visited = new HashSet <State <T> >();
// open list - Stack
Stack <State <T> > pending = new Stack <State <T> >();
pending.Push(searchable.GetInitialState());
while (pending.Count > 0)
{
State <T> currState = pending.Pop();
if (!visited.Contains(currState))
{
foreach (State <T> state in searchable.GetReachableStatesFrom(currState))
{
if (!pending.Contains(state) && !visited.Contains(state))
{
// found a new State - add to stack
pending.Push(state);
// add to the result tree as currState's child
resultTree.Add(state, currState);
}
}
}
visited.Add(currState);
}
return(resultTree);
}
/// <summary>
/// Searches the specified searchable.
/// </summary>
/// <param name="searchable">The searchable to search.</param>
/// <returns>
/// the search Path resulted by the search
/// </returns>
public PathSearchResult <T> Search(ISearchable <T> searchable)
{
TreeSearchResult <T> tree = this.DFSSearch(searchable);
State <T> goal = tree.Find(searchable.GetGoalState());
if (goal != null)
{
return(new PathSearchResult <T>(goal));
}
return(null);
}
/// <summary>
/// Branches the specified searchable.
/// </summary>
/// <param name="searchable">The searchable.</param>
/// <returns>
/// a Search States Tree
/// </returns>
public TreeSearchResult <T> Branch(ISearchable <T> searchable)
{
TreeSearchResult <T> result = new TreeSearchResult <T>(searchable.GetInitialState());
// closed list - HashSet
HashSet <State <T> > visited = new HashSet <State <T> >();
// opened list - RandomList
RandomList <State <T> > pending = new RandomList <State <T> >();
pending.RandomInsert(searchable.GetInitialState());
while (pending.Count > 0)
{
State <T> currState = pending.RandomRemoval();
if (!visited.Contains(currState))
{
foreach (State <T> state in searchable.GetReachableStatesFrom(currState))
{
if (!visited.Contains(state))
{
if (!pending.Contains(state))
{
// found a brand new State
pending.RandomInsert(state);
result.Add(state, currState);
}
else if (this.RandomBool())
{
// change the father of state in the tree
result.RemoveLeaf(state);
result.Add(state, currState);
}
}
}
visited.Add(currState);
}
}
return(result);
}