ChainCollector
Этот бот любит цепочки 1 . Он хочет как можно больше из них. Иногда он даже жертвует маленькой частью цепи, чтобы выиграть большую.
[1] Цепочка состоит из ручек, соединенных открытыми заборами, где каждая ручка имеет 1 или 2 открытых забора. Если можно закончить одну ручку, принадлежащую цепочке, то из-за правила чемпионата можно закончить и всю цепочку.
package pigpen.players;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.TreeMap;
import pigpen.Board;
import pigpen.Pen;
import pigpen.Player;
public class ChainCollector extends Player {
private enum Direction {
TOP, RIGHT, BOTTOM, LEFT;
public Direction opposite() {
return values()[(ordinal() + 2) % 4];
}
}
private enum ChainEndType {
OPEN, CLOSED, LOOP
}
private static class PenEx {
private final int id;
private final List<Fence> openFences = new ArrayList<>();
private boolean used = false;
public PenEx(int id) {
super();
this.id = id;
}
public void addOpenFence(Direction direction, PenEx child) {
openFences.add(new Fence(this, direction, child));
if (child != null) {
child.openFences.add(new Fence(child, direction.opposite(), this));
}
}
}
private static class Fence {
public final PenEx parent;
public final Direction direction;
public final PenEx child;
public Fence(PenEx parent, Direction direction, PenEx child) {
super();
this.parent = parent;
this.direction = direction;
this.child = child;
}
public int[] getMove() {
if (parent == null) {
return new int[] { child.id, direction.opposite().ordinal() };
} else {
return new int[] { parent.id, direction.ordinal() };
}
}
}
private static class Moves {
private final TreeMap<Integer, List<Fence>> map = new TreeMap<>();
public void add(int score, Fence move) {
List<Fence> list = map.get(score);
if (list == null) {
list = new ArrayList<>();
map.put(score, list);
}
list.add(move);
}
public boolean isEmpty() {
return map.isEmpty();
}
public boolean hasExactlyOne() {
return map.size() == 1 && map.firstEntry().getValue().size() == 1;
}
public int getLowestScore() {
return map.firstKey();
}
public int[] getLowMove() {
return map.firstEntry().getValue().get(0).getMove();
}
public int[] getHighMove() {
return map.lastEntry().getValue().get(0).getMove();
}
}
private static class BoardEx {
private final List<PenEx> pens = new ArrayList<>();
private final Moves neutralMoves = new Moves();
private final Moves finisherMoves = new Moves();
private final Moves safeFinisherMoves = new Moves();
private final Moves sacrificeMoves = new Moves();
private final Moves badMoves = new Moves();
public BoardEx(Board board) {
super();
PenEx[][] tmp = new PenEx[board.rows][board.cols];
for (int row = 0; row < board.rows; ++row) {
for (int col = 0; col < board.cols; ++col) {
Pen pen = board.getPenAt(row, col);
int[] fences = pen.fences();
PenEx penEx = new PenEx(pen.id());
tmp[row][col] = penEx;
pens.add(penEx);
if (fences[Pen.TOP] == 0) {
penEx.addOpenFence(Direction.TOP, row == 0 ? null : tmp[row - 1][col]);
}
if (row == board.rows - 1 && fences[Pen.BOTTOM] == 0) {
penEx.addOpenFence(Direction.BOTTOM, null);
}
if (fences[Pen.LEFT] == 0) {
penEx.addOpenFence(Direction.LEFT, col == 0 ? null : tmp[row][col - 1]);
}
if (col == board.cols - 1 && fences[Pen.RIGHT] == 0) {
penEx.addOpenFence(Direction.RIGHT, null);
}
}
}
}
private ChainEndType followChain(Fence begin, List<Fence> result) {
Fence current = begin;
for (;;) {
current.parent.used = true;
result.add(current);
if (current.child == null) {
return ChainEndType.OPEN;
}
List<Fence> childFences = current.child.openFences;
switch (childFences.size()) {
case 1:
current.child.used = true;
return ChainEndType.CLOSED;
case 2:
if (current.child == begin.parent) {
return ChainEndType.LOOP;
} else {
current = current.direction.opposite() == childFences.get(0).direction ?
childFences.get(1) : childFences.get(0);
}
break;
case 3:
case 4:
return ChainEndType.OPEN;
default:
throw new IllegalStateException();
}
}
}
public void findChains() {
for (PenEx pen : pens) {
if (!pen.used && pen.openFences.size() > 0) {
if (pen.openFences.size() < 3) {
List<Fence> fences = new ArrayList<>();
ChainEndType type1 = pen.openFences.size() == 1 ?
ChainEndType.CLOSED : followChain(pen.openFences.get(1), fences);
if (type1 == ChainEndType.LOOP) {
badMoves.add(fences.size(), fences.get(0));
} else {
Collections.reverse(fences);
ChainEndType type2 = followChain(pen.openFences.get(0), fences);
if (type1 == ChainEndType.OPEN && type2 == ChainEndType.CLOSED) {
type1 = ChainEndType.CLOSED;
type2 = ChainEndType.OPEN;
Collections.reverse(fences);
}
if (type1 == ChainEndType.OPEN) {
badMoves.add(fences.size() - 1, fences.get(fences.size() / 2));
} else if (type2 == ChainEndType.CLOSED) {
finisherMoves.add(fences.size() + 1, fences.get(0));
if (fences.size() == 3) {
sacrificeMoves.add(fences.size() + 1, fences.get(1));
} else {
safeFinisherMoves.add(fences.size() + 1, fences.get(0));
}
} else {
finisherMoves.add(fences.size(), fences.get(0));
if (fences.size() == 2) {
sacrificeMoves.add(fences.size(), fences.get(1));
} else {
safeFinisherMoves.add(fences.size(), fences.get(0));
}
}
}
} else {
pen.used = true;
for (Fence fence : pen.openFences) {
if (fence.child == null || fence.child.openFences.size() > 2) {
neutralMoves.add(fence.child == null ? 0 : fence.child.openFences.size(), fence);
}
}
}
}
}
}
public int[] bestMove() {
if (!neutralMoves.isEmpty()) {
if (!finisherMoves.isEmpty()) {
return finisherMoves.getHighMove();
}
return neutralMoves.getHighMove();
}
if (!safeFinisherMoves.isEmpty()) {
return safeFinisherMoves.getHighMove();
}
if (badMoves.isEmpty() && !finisherMoves.isEmpty()) {
return finisherMoves.getHighMove();
}
if (!sacrificeMoves.isEmpty()) {
if (sacrificeMoves.hasExactlyOne()) {
if (badMoves.getLowestScore() - sacrificeMoves.getLowestScore() >= 2) {
return sacrificeMoves.getLowMove();
} else {
return finisherMoves.getHighMove();
}
} else {
return finisherMoves.getHighMove();
}
}
if (!badMoves.isEmpty()) {
return badMoves.getLowMove();
}
return null;
}
}
@Override
public int[] pick(Board board, int id, int round) {
BoardEx boardEx = new BoardEx(board);
boardEx.findChains();
return boardEx.bestMove();
}
}
