private IList<Molecule> getCombinationsOfTwo(IList<Tile> potentialReactionTiles, Tile userClickedTile)
{
IList<Molecule> toReturn = new List<Molecule>();
Molecule combo;
for (int i = 0; i < potentialReactionTiles.Count; i++)
{
for (int j = i + 1; j < potentialReactionTiles.Count; j++)
{
combo = new Molecule();
combo.AtomTiles.Add(potentialReactionTiles[i]);
combo.AtomTiles.Add(potentialReactionTiles[j]);
// Bug-fix and optimization: only molecules with the user-clicked tile are legit.
if (combo.AtomTiles.Contains(userClickedTile))
{
toReturn.Add(combo);
}
}
}
return toReturn;
}
private IList<Molecule> calculateReactionsUsingBruteForceCombinations(IList<Tile> potentialReactionTiles, Tile userClickedTile)
{
IList<Molecule> toReturn = new List<Molecule>();
// Generate all possible combinations of (2 .. N) molecules.
// Since the internal function handles all the combinationing, we just
// call it with the biggest atom count, and it gets all the combinations of [2 .. N]
IList<Molecule> combos = getCombinationsOf(potentialReactionTiles.Count, potentialReactionTiles, userClickedTile);
return combos;
}
private IList<Molecule> getCombinationsOf(int i, IList<Tile> potentialReactionTiles, Tile userClickedTile)
{
// Is there a better way? Ionno.
// Let's return the FIRST molecule we find that matches. Instead of returning
// like 2000 potential molecules.
IList<Molecule> twos = new List<Molecule>();
IList<Molecule> threes = new List<Molecule>();
IList<Molecule> fours = new List<Molecule>();
IList<Molecule> fives = new List<Molecule>();
IList<Molecule> sixes = new List<Molecule>();
IList<Molecule> sevens = new List<Molecule>();
IList<Molecule> eights = new List<Molecule>();
IList<Molecule> nines = new List<Molecule>();
// Our "working set" of "do we have anything?"
IList<Molecule> temp = new List<Molecule>();
if (i >= 2)
{
twos = getCombinationsOfTwo(potentialReactionTiles, userClickedTile);
temp = twos.Where(m => m.NetCharge == 0).ToList();
if (temp.Count > 0)
{
temp = weedOutNonConnectedMolecules(temp);
if (temp.Count > 0)
{
return temp;
}
}
}
if (i >= 3)
{
threes = getIncrementalCombinations(potentialReactionTiles, twos);
temp = threes.Where(m => m.NetCharge == 0).ToList();
if (temp.Count > 0)
{
temp = weedOutNonConnectedMolecules(temp);
if (temp.Count > 0)
{
return temp;
}
}
}
if (i >= 4)
{
// Optimize: dump un-needed stuff
twos.Clear();
fours = getIncrementalCombinations(potentialReactionTiles, threes);
temp = fours.Where(m => m.NetCharge == 0).ToList();
if (temp.Count > 0)
{
temp = weedOutNonConnectedMolecules(temp);
if (temp.Count > 0)
{
return temp;
}
}
}
if (i >= 5)
{
threes.Clear();
fives = getIncrementalCombinations(potentialReactionTiles, fours);
temp = fives.Where(m => m.NetCharge == 0).ToList();
if (temp.Count > 0)
{
temp = weedOutNonConnectedMolecules(temp);
if (temp.Count > 0)
{
return temp;
}
}
}
if (i >= 6)
{
fours.Clear();
sixes = getIncrementalCombinations(potentialReactionTiles, fives);
temp = sixes.Where(m => m.NetCharge == 0).ToList();
if (temp.Count > 0)
{
temp = weedOutNonConnectedMolecules(temp);
if (temp.Count > 0)
{
return temp;
}
}
}
if (i >= 7)
{
fives.Clear();
sevens = getIncrementalCombinations(potentialReactionTiles, sixes);
temp = sevens.Where(m => m.NetCharge == 0).ToList();
if (temp.Count > 0)
{
temp = weedOutNonConnectedMolecules(temp);
if (temp.Count > 0)
{
return temp;
}
}
}
if (i >= 8)
{
sixes.Clear();
eights = getIncrementalCombinations(potentialReactionTiles, sevens);
temp = eights.Where(m => m.NetCharge == 0).ToList();
if (temp.Count > 0)
{
temp = weedOutNonConnectedMolecules(temp);
if (temp.Count > 0)
{
return temp;
}
}
}
if (i >= 9)
{
sevens.Clear();
nines = getIncrementalCombinations(potentialReactionTiles, eights);
temp = nines.Where(m => m.NetCharge == 0).ToList();
if (temp.Count > 0)
{
temp = weedOutNonConnectedMolecules(temp);
if (temp.Count > 0)
{
return temp;
}
}
}
// Didn't find it yet and return? Sucks to be you!
return new List<Molecule>();
}
// Our real, core algorithm. Let's do it!
internal IList<Tile> GetTilesInReaction(Tile newAtomTile)
{
// get all adjacent atoms. True = base case
IList<Tile> potentialReactionTiles = new List<Tile>();
this.getPotentialReactionTiles(newAtomTile, potentialReactionTiles);
// It's fast, and it's great, but fails in wierd cases.
// Like B-Fl-Fl-Fl, where you place the Fl closest to the B last.
// If we carry over connected atoms, this case works, but other cases bork.
// Like this case:
// B Fl
// B Fl
// Fl
IList<Molecule> potentialMolecules = this.calculateReactionsUsingBestFirstSearch(potentialReactionTiles, newAtomTile, new List<Tile>(), new List<Tile>());
// If best-first didn't find anything, revert to brute-froce.
if (potentialMolecules.Count == 0)
{
potentialMolecules = this.calculateReactionsUsingBruteForceCombinations(potentialReactionTiles, newAtomTile);
}
// All of the following calls are not necessary in the brute-force case.
// But the performance is trivial, so, do it anyway to simplify the code.
// Weed out net != 0
potentialMolecules = potentialMolecules.Where(m => m.NetCharge == 0).ToList();
// Fix for bug where you can form |-shaped HCl around a Beryllium atom
potentialMolecules = weedOutNonConnectedMolecules(potentialMolecules);
// Sort by electronegativity, get the top result
Molecule formedMolecule = getMostElectronegative(potentialMolecules);
IList<Tile> toReturn = new List<Tile>();
if (formedMolecule != null)
{
foreach (Tile t in formedMolecule.AtomTiles)
{
toReturn.Add(t);
}
}
return toReturn;
}
// It's complicated. We use two collections: one that looks at ALL the atoms we see, ever,
// and one that looks at only the atoms we've seen so far -- the latter back-pedals when
// we run out of adjacencies, and the former perseveres. This covers all kinds of cases,
// like (* indicates last atom placed):
// B Fl
// B Fl
// Fl*
// ... which is covered by back-pedalling only, and like:
// B Cl* Cl Cl
// ... which is covered by looking at the total only.
private IList<Molecule> calculateReactionsUsingBestFirstSearch(IList<Tile> potentialReactionTiles, Tile centerTile, IList<Tile> foundSoFarInPath, IList<Tile>foundSoFarInTotal)
{
// These IFs cover a tricky case where we search exhaustively and don't find
// a molecule, then when backtracking, backtrack into something we've seen
// already. We shouldn't add a tile twice, and this fixes the bug that does that
// (visible in puzzle one -- it adds the bottom-most Fl twice (6, 3).)
if (!foundSoFarInPath.Contains(centerTile))
{
foundSoFarInPath.Add(centerTile);
}
if (!foundSoFarInTotal.Contains(centerTile))
{
foundSoFarInTotal.Add(centerTile);
}
Molecule m1 = new Molecule();
foreach (Tile t in foundSoFarInPath)
{
m1.AtomTiles.Add(t);
}
if (m1.NetCharge == 0)
{
// Base case: we're net zero!
List<Molecule> toReturn = new List<Molecule>();
toReturn.Add(m1);
return toReturn;
}
Molecule m2 = new Molecule();
foreach (Tile t in foundSoFarInTotal)
{
m2.AtomTiles.Add(t);
}
if (m2.NetCharge == 0)
{
// Base case: we're net zero!
List<Molecule> toReturn = new List<Molecule>();
toReturn.Add(m2);
return toReturn;
}
// Recursive case: keep looking.
// Find adjacent molecules
IList<Tile> adjacents = potentialReactionTiles.Where(t => TowerUtils.DistanceBetweenPoints(t.X, t.Y, centerTile.X, centerTile.Y) == 1).ToList();
// Exclude tiles we already saw. Use current path, for back-pedalling.
adjacents = adjacents.Where(t => !foundSoFarInPath.Contains(t) && !foundSoFarInTotal.Contains(t)).ToList();
// Sort by |my valence + their valence|;
adjacents = adjacents.OrderBy(t => t, new OrderTilesByElectronegativityWithAtomComparer(centerTile.Atom)).ToList();
// Base case: no adjacents.
if (adjacents.Count == 0)
{
return new List<Molecule>();
}
else
{
// Take the best, and move on
foreach (Tile adj in adjacents)
{
// Copy foundSoFar so we can return up the stack and keep looking on
// a different path. Without screwing up our "found so far" data.
IList<Tile> foundDupe = new List<Tile>();
foreach (Tile t in foundSoFarInPath)
{
foundDupe.Add(t);
}
IList<Molecule> toReturn = this.calculateReactionsUsingBestFirstSearch(potentialReactionTiles, adj, foundDupe, foundSoFarInTotal);
if (toReturn.Count > 0)
{
return toReturn;
}
}
// Found nothing.
return new List<Molecule>();
}
}
private bool tileFollowsDifficultyBalancingAlgorithm(Tile current, Atom proposedAtom)
{
IList<Tile> adjacents = this.getNonEmptyAdjacentTiles(current);
if (adjacents.Count == 0)
{
return true;
}
else
{
IList<Tile> oppositeValence;
if (proposedAtom.IonCharge > 0)
{
oppositeValence = adjacents.Where(t => t.Atom.IonCharge < 0).ToList();
}
else
{
oppositeValence = adjacents.Where(t => t.Atom.IonCharge > 0).ToList();
}
// Fail if 50% or more of atoms are opposite valence
if (oppositeValence.Count >= 0.5 * adjacents.Count)
{
return false;
}
else
{
return true;
}
}
}
/// <summary>
/// Get potential reaction tiles. These are non-empty tiles
/// that are non-diagonally adjacent to centerTile.
/// This also includes tiles that are adjacent to adjacent tiles.
/// </summary>
/// <param name="centerTile"></param>
/// <returns></returns>
private void getPotentialReactionTiles(Tile centerTile, IList<Tile> toReturn)
{
if (!toReturn.Contains(centerTile))
{
toReturn.Add(centerTile);
}
IList<Tile> temp = getNonEmptyAdjacentTiles(centerTile);
foreach (Tile t in temp.Where(t => !toReturn.Contains(t)))
{
// Take adjacencies to all our atoms.
getPotentialReactionTiles(t, toReturn);
}
}
private IList<Tile> getNonEmptyAdjacentTiles(Tile centerTile)
{
IList<Tile> toReturn = new List<Tile>();
if (centerTile.X > 0)
{
// left
toReturn.Add(this._board[centerTile.X - 1, centerTile.Y]);
}
if (centerTile.X < BOARD_WIDTH - 1)
{
// right
toReturn.Add(this._board[centerTile.X + 1, centerTile.Y]);
}
if (centerTile.Y > 0)
{
toReturn.Add(this._board[centerTile.X, centerTile.Y - 1]);
}
if (centerTile.Y < BOARD_HEIGHT - 1)
{
toReturn.Add(this._board[centerTile.X, centerTile.Y + 1]);
}
return toReturn.Where(t => !t.IsEmpty()).ToList();
}
private void fadeTileIn(Tile t)
{
// Be yellow. Fade in.
t.AtomSprite.ColorOperation = ColorOperation.Add;
t.AtomSprite.Red = 1;
t.AtomSprite.Green = 1;
t.AtomSprite.RedRate = -1;
t.AtomSprite.GreenRate = -1;
this._fadingInTiles.Add(t);
}
private void drawTile(Tile t)
{
if (!t.IsEmpty())
{
Atom a = t.Atom;
Sprite s = this.AddSprite("Content/Atoms/" + a.Element + ".png");
s.X = (t.X * 50) - CENTER_OF_BOARD_X;
s.Y = (t.Y * -50) + CENTER_OF_BOARD_Y;
Text e = this.AddText(a.Element);
e.Scale = 16;
e.HorizontalAlignment = FlatRedBall.Graphics.HorizontalAlignment.Center;
e.X = s.X;
e.Y = s.Y;
// Do some clean-up. Just incase.
if (t.AtomSprite != null)
{
this.RemoveResource(t.AtomSprite);
}
if (t.AtomText != null)
{
this.RemoveResource(t.AtomText);
}
t.AtomSprite = s;
t.AtomText = e;
}
}