public AStarSearch()
{
id = "AS";
name = "A* Search";
iterationCount = 0;
category = SearchCategory.Informed;
Frontier = new Frontier();
Searched = new List <MazeState>();
}
public GreedyBestFirstSearch()
{
id = "GBFS";
name = "Greedy Best First Search";
iterationCount = 0;
category = SearchCategory.Informed;
Frontier = new Frontier();
Searched = new List <MazeState>();
}
public BreadthFirstSearch()
{
id = "BFS";
name = "Breadth-First Search";
iterationCount = 0;
category = SearchCategory.Uninformed;
Frontier = new Frontier();
Searched = new List <MazeState>();
}
public UniformCostSearch()
{
id = "UCS";
name = "Uniform Cost Search";
iterationCount = 0;
category = SearchCategory.Uninformed;
Frontier = new Frontier();
Searched = new List <MazeState>();
}
public override bool AddToFrontier(MazeState aState, Frontier aFrontier = null)
{
Frontier selectedFrontier = aFrontier == null ? Frontier : aFrontier;
if (selectedFrontier.Contains(aState) || Maze.Contains(aState, Searched))
{
return(false);
}
else
{
selectedFrontier.Enqueue(aState);
}
return(true);
}
public override Direction[] Solve(Maze aMaze)
{
//push the StartState to the frontier
AddToFrontier(aMaze.StartState);
while (!Frontier.Empty())
{
//Pop frontier state into curState
MazeState curState = PopFrontier();
//check if curState is a goalState
//using a loop for each of the varient goal states listed
for (int i = 0; i < aMaze.GoalStates.Length; i++)
{
if (Maze.AreEqual(curState.State, aMaze.GoalStates[i].State))
{
Maze.OutputState(curState.State);
aMaze.FinalPathCost = curState.Cost;
Console.WriteLine($"Path cost: {aMaze.FinalPathCost}");
iterationCount++;
return(curState.GetPathFromParent());
}
}
//Find most desirable goal state - i.e. which is closes to the current state
MazeState ClosestGoal = PickDesiredGoalState(curState, aMaze.GoalStates);
//get all possible new states from curState
List <MazeState> newStates = curState.CreatePossibleMoves();
//add all children frontier
foreach (MazeState s in newStates)
{
//Need to implement a way to have a heuristic cost for each of the goal states
s.HeuristicCost = GetManhattanDistance(s, ClosestGoal);
AddToFrontier(s);
}
//Sort the frontier by f(n) = g(n) + h(n)
Frontier.SortByEvaluationCost();
iterationCount++;
}
return(null);
}
public override Direction[] Solve(Maze aMaze)
{
//ensure variable cost mode is on
SearchMethod.VariableCost = true;
AddToFrontier(aMaze.StartState);
while (!Frontier.Empty())
{
//Pop frontier state into curState
MazeState curState = Frontier.Pop();
Searched.Add(curState);
//check if curState is a goalState
//using a loop for each of the varient goal states listed
for (int i = 0; i < aMaze.GoalStates.Length; i++)
{
if (Maze.AreEqual(curState.State, aMaze.GoalStates[i].State))
{
Maze.OutputState(curState.State);
aMaze.FinalPathCost = curState.Cost;
Console.WriteLine($"Path cost: {aMaze.FinalPathCost}");
iterationCount++;
return(curState.GetPathFromParent());
}
}
//get all possible new states from curState
List <MazeState> newStates = curState.CreatePossibleMoves();
foreach (MazeState s in newStates)
{
AddToFrontier(s);
}
iterationCount++;
Frontier.SortByCost();
}
return(null);
}
public override Direction[] Solve(Maze aMaze)
{
//push the StartState to the frontier
AddToFrontier(aMaze.StartState);
while (!Frontier.Empty())
{
//Pop frontier state into curState
MazeState curState = Frontier.Dequeue();
Searched.Add(curState);
//check if curState is a goalState
//using a loop for each of the varient goal states listed
for (int i = 0; i < aMaze.GoalStates.Length; i++)
{
if (Maze.AreEqual(curState.State, aMaze.GoalStates[i].State))
{
Maze.OutputState(curState.State);
aMaze.FinalPathCost = curState.Cost;
Console.WriteLine($"Path cost: {aMaze.FinalPathCost}");
iterationCount++;
return(curState.GetPathFromParent());
}
}
//get all possible new states from curState
List <MazeState> newStates = curState.CreatePossibleMoves();
newStates.Reverse(); //Reverse elements to ensure priority is U > L > D > R
foreach (MazeState s in newStates)
{
AddToFrontier(s);
}
iterationCount++;
}
return(null);
}
public void Reset()
{
Frontier = new Frontier();
Searched = new List <MazeState>();
iterationCount = 0;
}
public abstract bool AddToFrontier(MazeState aState, Frontier aFrontier = null);