public override int Evaluate(PuzzleState state, PuzzleState goalState)
{
int manhanttanDist = 0;
var possibleRowConflicts = new Dictionary <int, List <Tuple <int, int> > >();
var possibleColConflicts = new Dictionary <int, List <Tuple <int, int> > >();
for (int i = 0; i < 4; i++)
{
for (int j = 0; j < 4; j++)
{
int val = state.Board[i, j];
if (val == 0)
{
continue;
}
var correctPos = goalState.GetSpace(val);
manhanttanDist += ManhattanDistanceHeuristic.ManhattanDistance(i, j, correctPos.Row, correctPos.Col);
// check for linear conflicts in the horizontal + vertical direction
if (i == correctPos.Row && j != correctPos.Col)
{
if (!possibleRowConflicts.ContainsKey(i))
{
possibleRowConflicts[i] = new List <Tuple <int, int> >();
}
possibleRowConflicts[i].Add(Tuple.Create(j, correctPos.Col));
}
if (j == correctPos.Col && i != correctPos.Row)
{
if (!possibleColConflicts.ContainsKey(j))
{
possibleColConflicts[j] = new List <Tuple <int, int> >();
}
possibleColConflicts[j].Add(Tuple.Create(i, correctPos.Row));
}
}
}
// Calculate the # of linear conflicts
int linearConflicts = 0;
foreach (List <Tuple <int, int> > possibleConflicts in possibleRowConflicts.Values.Concat(possibleColConflicts.Values))
{
Tuple <int, int> conflict = possibleConflicts.First();
linearConflicts += possibleConflicts.Skip(1).Count(x => (x.Item1 > conflict.Item1 && x.Item2 < conflict.Item2) ||
(x.Item1 <conflict.Item1 && x.Item2> conflict.Item2));
}
return(manhanttanDist + 2 * linearConflicts);
}
public override int Evaluate(PuzzleState state, PuzzleState goal)
{
var manhattanDistanceOff = 0;
var possibleRowConflicts = new Dictionary <byte, List <Tuple <byte, byte> > >();
var possibleColConflicts = new Dictionary <byte, List <Tuple <byte, byte> > >();
for (byte i = 0; i < 4; i++)
{
for (byte j = 0; j < 4; j++)
{
var val = state.Board[i, j];
if (val == 0)
{
continue; // skip the blank
}
var correctPlace = goal.GetSpace(val);
manhattanDistanceOff += ManhattanDistanceHeuristic.ManhattanDistance(i, j, correctPlace.Row, correctPlace.Col);
// now check for linear conflicts
// in correct row and wrong column?
if (i == correctPlace.Row && j != correctPlace.Col)
{
if (!possibleRowConflicts.ContainsKey(i))
{
possibleRowConflicts[i] = new List <Tuple <byte, byte> >();
}
possibleRowConflicts[i].Add(Tuple.Create(j, correctPlace.Col));
}
// in correct col and wrong row?
if (j == correctPlace.Col && i != correctPlace.Row)
{
if (!possibleColConflicts.ContainsKey(j))
{
possibleColConflicts[j] = new List <Tuple <byte, byte> >();
}
possibleColConflicts[j].Add(Tuple.Create(i, correctPlace.Row));
}
}
}
var linearConflicts = 0;
foreach (var possibleConflicts in possibleRowConflicts.Values.Concat(possibleColConflicts.Values))
{
var conflict = possibleConflicts.First();
linearConflicts += possibleConflicts.Skip(1).Count(x => (x.Item1 > conflict.Item1 && x.Item2 < conflict.Item2) ||
(x.Item1 <conflict.Item1 && x.Item2> conflict.Item2));
}
return(manhattanDistanceOff + 2 * linearConflicts);
}