/// <summary>
/// Main method from where the execution starts
/// Accepts the input from user
/// </summary>
/// <param name="args"></param>
static void Main(string[] args)
{
int input;
Console.Write("Enter the size of board: ");
while (true)
{
if (Int32.TryParse(Console.ReadLine(), out input))
{
break;
}
else
{
Console.WriteLine("Enter a valid number: ");
}
}
NQueensProblem nqueens;
bool flag = true;
//initialize the object until a solution is found for CSP
do
{
nqueens = new NQueensProblem(input);
nqueens.InitializeBoard();
if (flag)
{
Console.WriteLine("Initial State");
nqueens.PrintState();
Console.WriteLine("======HILL CLIMBING======");
//Call the HillClimbing method
NQueensProblem result = HillClimbingProblem.HillClimbing(nqueens);
result.PrintState();
Console.WriteLine("Number of Random Initializations are {0}", numberOfInits);
Console.WriteLine("Number of State changes are {0}", numberOfSteps);
flag = false;
numberOfInits = 0;
Console.WriteLine("\n=========CSP===========");
}
numberOfInits++;
numberOfSteps = 0;
nqueens = CSP.MinConlicts(nqueens, 100);
} while (nqueens == null);
nqueens.PrintState();
Console.WriteLine("Number of Random Initializations are {0}", numberOfInits);
Console.WriteLine("Number of State changes are {0}", numberOfSteps);
Console.Read();
}
/// <summary>
/// Takes the initialState as the parameter
/// generates its successors and select the best successor based on heuristic
/// </summary>
/// <param name="initialState"></param>
/// <returns></returns>
public static NQueensProblem HillClimbing(NQueensProblem initialState)
{
NQueensProblem current = initialState;
while (true)
{
if (Program.numberOfSteps < 100)
{
//Generate the successors
List <NQueensProblem> successors = current.Successors();
List <NQueensProblem> bestSuccessor = new List <NQueensProblem>();
bestSuccessor.Add(successors[0]);
//Select the best successor
foreach (NQueensProblem successor in successors)
{
if (successor.Conflicts == bestSuccessor[0].Conflicts)
{
bestSuccessor.Add(successor);
}
else if (successor.Conflicts < bestSuccessor[0].Conflicts)
{
bestSuccessor.Clear();
bestSuccessor.Add(successor);
}
}
Program.numberOfSteps++;
Random random = new Random();
int chooseOneSuccessor = random.Next(bestSuccessor.Count);
//if current better than best successor return current
if (bestSuccessor[chooseOneSuccessor].Conflicts > current.Conflicts)
{
return(current);
}
//else set current to best successor
current = bestSuccessor[chooseOneSuccessor];
}
else
{
//enters here if the Hill-Climbing is stuck due to local maximum or plateau or ridge
Program.numberOfInits++;
Program.numberOfSteps = 0;
initialState.InitializeBoard();
return(HillClimbing(initialState));
}
}
}
/// <summary>
/// Main method from where the execution starts
/// Accepts the input from user
/// </summary>
/// <param name="args"></param>
static void Main(string[] args)
{
int input;
Console.Write("Enter the size of board: ");
while(true)
{
if (Int32.TryParse(Console.ReadLine(), out input)) break;
else Console.WriteLine("Enter a valid number: ");
}
NQueensProblem nqueens ;
bool flag = true;
//initialize the object until a solution is found for CSP
do
{
nqueens = new NQueensProblem(input);
nqueens.InitializeBoard();
if(flag)
{
Console.WriteLine("Initial State");
nqueens.PrintState();
Console.WriteLine("======HILL CLIMBING======");
//Call the HillClimbing method
NQueensProblem result = HillClimbingProblem.HillClimbing(nqueens);
result.PrintState();
Console.WriteLine("Number of Random Initializations are {0}", numberOfInits);
Console.WriteLine("Number of State changes are {0}", numberOfSteps);
flag = false;
numberOfInits = 0;
Console.WriteLine("\n=========CSP===========");
}
numberOfInits++;
numberOfSteps = 0;
nqueens = CSP.MinConlicts(nqueens, 100);
} while (nqueens == null);
nqueens.PrintState();
Console.WriteLine("Number of Random Initializations are {0}", numberOfInits);
Console.WriteLine("Number of State changes are {0}", numberOfSteps);
Console.Read();
}
/// <summary>
/// Takes the initialState as the parameter
/// generates its successors and select the best successor based on heuristic
/// </summary>
/// <param name="initialState"></param>
/// <returns></returns>
public static NQueensProblem HillClimbing(NQueensProblem initialState)
{
NQueensProblem current = initialState ;
while(true)
{
if (Program.numberOfSteps < 100)
{
//Generate the successors
List<NQueensProblem> successors = current.Successors();
List<NQueensProblem> bestSuccessor= new List<NQueensProblem>() ;
bestSuccessor.Add(successors[0]);
//Select the best successor
foreach (NQueensProblem successor in successors)
{
if (successor.Conflicts == bestSuccessor[0].Conflicts)
bestSuccessor.Add(successor);
else if (successor.Conflicts < bestSuccessor[0].Conflicts)
{
bestSuccessor.Clear();
bestSuccessor.Add ( successor);
}
}
Program.numberOfSteps++;
Random random = new Random();
int chooseOneSuccessor = random.Next (bestSuccessor .Count );
//if current better than best successor return current
if (bestSuccessor[chooseOneSuccessor].Conflicts > current.Conflicts) return current;
//else set current to best successor
current = bestSuccessor[chooseOneSuccessor];
}
else
{
//enters here if the Hill-Climbing is stuck due to local maximum or plateau or ridge
Program.numberOfInits++;
Program.numberOfSteps = 0;
initialState.InitializeBoard();
return HillClimbing(initialState);
}
}
}