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| − | {{code}}
| + | <a href="http://somacn.com/">buy generic soma</a> |
| − | package player;
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| − |
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| − | /* Gameboard class
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| − | * contains the gameboard ADT and methods for handling it
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| − | * in addition, contains methods for generating and evaluating new moves
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| − | **/
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| − |
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| − | public class Gameboard {
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| − |
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| − | // Allows for a hypothetical expansion of the board
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| − | public final static int DIMENSION = 8;
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| − | public final static int ADD = 1;
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| − | public final static int STEP = 2;
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| − | // used for signaling a white/black win; needs to be large and prime
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| − | public final static int WHITEWIN = 2047;
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| − | public final static int BLACKWIN = -2047;
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| − |
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| − | private Chip[][] board = new Chip[DIMENSION][DIMENSION];
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| − | private int x = DIMENSION;
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| − | private int y = DIMENSION;
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| − | private int pieces;
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| − |
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| − | // returns the Chip at a given x & y coord
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| − | /* we use a "try" so that if we try to access a location that is off the board,
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| − | i.e. we attempt to get non-existent coords, then just return null */
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| − | public Chip cellContents(int x, int y) {
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| − | try {
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| − | return board[x][y];
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| − | } catch (ArrayIndexOutOfBoundsException e) {
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| − | return null;
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| − | }
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| − | }
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| − |
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| − | /** @return an array of Chip neighbors around a given position (x,y) **/
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| − | public Chip[] neighborarray(int x, int y) {
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| − | Chip[] array = new Chip[8];
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| − | array[0] = cellContents(x-1, y-1); // nw
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| − | array[1] = cellContents(x, y-1); // n
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| − | array[2] = cellContents(x+1, y-1); // ne
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| − | array[3] = cellContents(x+1, y); // e
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| − | array[4] = cellContents(x+1, y+1); // se
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| − | array[5] = cellContents(x, y+1); // s
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| − | array[6] = cellContents(x-1, y+1); // sw
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| − | array[7] = cellContents(x-1, y); // w
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| − | return array;
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| − | }
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| − |
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| − | /** takes in rec = 1 on initial search
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| − | @return the number of the same-color neighbors around a given position (x, y) **/
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| − | public int neighbor(int color, int x, int y, int rec) {
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| − | if (rec < 0) {
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| − | return 0;
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| − | } else {
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| − | Chip[] array = neighborarray(x, y);
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| − | int number = 0;
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| − | for (int i=0; i<array.length; i++) {
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| − | Chip target = array[i];
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| − | if (target != null && target.getColor()==color) {
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| − | number = number + neighbor(color, target.getX(), target.getY(), rec-1);
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| − | number++;
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| − | }
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| − | }
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| − | return number;
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| − | }
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| − | }
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| − |
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| − | /* inserts a chip of the given color at (x, y) if this is acceptable
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| − | returns true if the insertion is legal, false otherwise */
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| − | public boolean insertChip(int color, int x, int y) {
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| − | if (validMove(color, new Move(x, y))) {
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| − | board[x][y] = new Chip(color, x, y);
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| − | pieces++;
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| − | return true;
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| − | } else {
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| − | return false;
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| − | }
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| − | }
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| − |
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| − | /* moves Chip c to a new location at (x, y)
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| − | returns true if the move is legal, false otherwise */
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| − | public boolean moveChip(Chip c, int x, int y) {
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| − | if (validMove(c.getColor(), new Move(x, y))) {
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| − | board[c.getX()][c.getY()] = null;
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| − | board[x][y] = new Chip(c.getColor(), x, y);
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| − | return true;
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| − | } else {
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| − | return false;
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| − | }
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| − | }
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| − |
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| − | /* performs the requested move for a player of the given color
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| − | returns true if the move is legal, false otherwise */
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| − | public boolean performMove(int color, Move m) {
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| − | if (m.moveKind == Move.ADD) {
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| − | return insertChip(color, m.x1, m.y1);
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| − | } else if (m.moveKind == Move.STEP) {
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| − | return moveChip(retrieveChip(m.x2, m.y2), m.x1, m.y1);
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| − | } else {
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| − | return true;
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| − | }
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| − | }
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| − |
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| − | // legacy method for returning a chip at (x, y)
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| − | public Chip retrieveChip(int x, int y) {
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| − | return cellContents(x, y);
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| − | }
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| − |
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| − | /** Verifies that a given move is valid for a plyer of the given color.
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| − | * the following conditions must be met:
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| − | * No chip may be placed in any of the four corners
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| − | * No chip may be placed in a goal of the opposite color
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| − | * No chip may be placed in a square that is already occupied
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| − | * A player may not have more than two chips in a connected group, whether connected orthogonally or diagonally
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| − | takes a move and the player's color performing the move
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| − | @return true if move is valid
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| − | */
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| − | public boolean validMove(int color, Move m) {
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| − | if (m.moveKind == Move.QUIT) {
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| − | return true;
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| − | } else {
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| − | if ((m.x1==0 && (m.y1==0 || m.y1==DIMENSION-1)) || (m.y1==DIMENSION-1 && (m.x1==0 || m.x1==DIMENSION-1))) {
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| − | return false; // in the corners
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| − | } else if (board[m.x1][m.y1] != null) {
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| − | return false; // target cell isn't empty
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| − | } else if (((color == Chip.BLACK) && (m.x1==0 || m.x1==DIMENSION-1)) || ((color == Chip.WHITE) && (m.y1==0 || m.y1==DIMENSION-1))) {
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| − | return false; // target cell is in opponent's goal
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| − | } else if (!checkClusterSize(color, m.x1, m.y1)) {
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| − | return false; // resulting cluster too big
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| − | } else {
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| − | return true; // looks like this move is good
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| − | }
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| − | }
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| − | }
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| − |
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| − | // helper method for validMove()
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| − | // @return true if an insertion at the given position is possible w/respect to cluster size; false otherwise
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| − | public boolean checkClusterSize(int color, int x, int y) {
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| − | if (neighbor(color, x, y, 1) > 1) {
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| − | return false;
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| − | } else {
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| − | return true;
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| − | }
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| − | }
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| − |
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| − | // generates a 2-d array of moves and resulting gameboards for a given color
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| − | // @return[0] is an array of Gameboards (Gameboard[x])
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| − | // @return[1] is an array of Moves corresponding to each board in return[0] (Move[x])
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| − | // thus the board after performing g.performMove(color, return[1][i]) is return[0][i]
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| − | public Object[][] generateMoves(int color) {
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| − | {{notmine|Chanh Vo|fragment=yes}}
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| − | }
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| − |
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| − | // @return an exact clone of "this" gameboard
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| − | public Gameboard clone() {
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| − | {{notmine|Chanh Vo|fragment=yes}}
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| − | }
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| − |
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| − | // return the current Move kind for this gameboard, depending on number of pieces
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| − | // @return either STEP or ADD
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| − | public int moveKind() {
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| − | if (pieces < 20) {
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| − | return ADD;
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| − | } else {
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| − | return STEP;
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| − | }
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| − | }
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| − |
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| − | /* chooses a move to a given depth for a given color using alpha-beta pruning (hopefully)
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| − | / first two moves involve the random placement of a chip in each of the goals without any analysis
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| − | / @param color - current player's color
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| − | depth - number of levels remaining to search (i.e. depth = 1 means no look-ahead)
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| − | alpha, beta - best-case and worst-case scores
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| − | side - true for white, false for black
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| − | factor - multiplier used to score a win many levels down lower than a win in the first level
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| − | / @return an Alphamove with the best move and its corresponding score */
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| − | public Alphamove chooseMove(int color, int depth, int alpha, int beta, boolean side, int factor) {
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| − | Alphamove bestme = new Alphamove();
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| − | Alphamove bestopp;
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| − | if (side) {
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| − | bestme.score = alpha;
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| − | } else {
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| − | bestme.score = beta;
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| − | }
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| − | if (pieces < 2) { // first move for each color
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| − | // place a random piece in the top (black) or left (white) goal
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| − | int target = (((int) (Math.random() * 10.0)) % (DIMENSION - 2)) + 1;
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| − | if (color == Chip.BLACK) {
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| − | bestme.move = new Move(target, 0);
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| − | } else {
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| − | bestme.move = new Move(0, target);
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| − | }
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| − | return bestme;
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| − | } else if (pieces < 4) { // second move for each color
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| − | // place a random piece in the bottom (black) or right (white) goal
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| − | int target = (((int) (Math.random() * 10.0)) % (DIMENSION - 2)) + 1;
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| − | if (color == Chip.BLACK) {
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| − | bestme.move = new Move(target, DIMENSION-1);
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| − | } else {
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| − | bestme.move = new Move(DIMENSION-1, target);
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| − | }
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| − | return bestme;
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| − | } else {
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| − | // at least 4 pieces are on the board now, so this is the 3rd+ move
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| − | // go ahead and generate the possible moves from the current board
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| − | Object[][] arr = generateMoves(color);
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| − | if (depth == 1) {
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| − | // this is our last level, so end the recursion
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| − | for (int i=0; i<arr[0].length; i++) {
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| − | if (arr[0][i] != null) {
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| − | Move targetmove = (Move) arr[1][i];
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| − | int score = ((Gameboard) arr[0][i]).winner()*factor;
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| − | System.out.println("Got score " + score + " for board " + ((Gameboard) arr[0][i]) + ", factor " + factor);
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| − | if ((((score/factor)==WHITEWIN) && (color==Chip.WHITE)) || (((score/factor)==BLACKWIN) && (color==Chip.BLACK))) {
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| − | // we've reached a winner, so stop here and return it
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| − | bestme.score = score;
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| − | bestme.move = targetmove;
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| − | return bestme;
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| − | } else if ((score > bestme.score && side) || (score < bestme.score && !side)) {
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| − | bestme.score = score;
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| − | bestme.move = targetmove;
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| − | }
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| − | } else { // we've run out of moves to evalute; stop
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| − | break;
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| − | }
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| − | }
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| − | return bestme;
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| − | } else {
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| − | for (int ii=0; ii<arr[0].length; ii++) {
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| − | if (arr[0][ii] != null) {
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| − | // eventually, this is where we will check to make sure we still have enough time
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| − | System.out.println("side: " + side);
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| − | Move targetmove = (Move) arr[1][ii];
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| − | int score = ((Gameboard) arr[0][ii]).winner()*factor;
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| − | if (depth ==2) { System.out.println("Got score " + score + " for board " + ((Gameboard) arr[0][ii]) + ", factor " + factor); }
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| − | if ((((score/factor)==WHITEWIN) && (color==Chip.WHITE)) || (((score/factor)==BLACKWIN) && (color==Chip.BLACK))) {
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| − | // we've reached a winner, so stop here and return it
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| − | bestme.score = score;
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| − | bestme.move = targetmove;
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| − | return bestme;
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| − | } else {
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| − | bestopp = ((Gameboard) arr[0][ii]).chooseMove(generateOpponent(color), depth-1, alpha, beta, !side, factor-1); //hopefully we never search for more than 9 levels...
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| − | System.out.println("Opponent's best response is " + bestopp.score + ", current best score is " + bestme.score + " (side && (bestopp.score > bestme.score)) returns " + (side && (bestopp.score > bestme.score)) + " for side = " + side);
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| − | targetmove = (Move) arr[1][ii];
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| − | if (side && (bestopp.score > bestme.score)) {
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| − | bestme.move = targetmove;
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| − | bestme.score = bestopp.score;
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| − | alpha = bestopp.score;
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| − | System.out.println("Found better move for white, score is " + bestopp.score + " move is " + bestme.move);
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| − | } else if (!side && (bestopp.score < bestme.score)) {
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| − | bestme.move = targetmove;
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| − | bestme.score = bestopp.score;
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| − | beta = bestopp.score;
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| − | // System.out.println("Found better move for black, score is " + bestopp.score);
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| − | } if (alpha >= beta) {
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| − | return bestme;
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| − | }
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| − | }
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| − | } else { // we've run out of moves to evalute; stop
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| − | break;
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| − | }
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| − | }
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| − | return bestme;
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| − | }
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| − | }
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| − | }
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| − |
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| − | // returns the best possible move that can be made by the given color to a search depth of "depth" using the "this" board
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| − | // @return the best current Move
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| − | public Move evalTree(int color, int depth) {
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| − | int alpha = (BLACKWIN*10)-1;
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| − | int beta = (WHITEWIN*10)+1;
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| − | boolean side;
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| − | if (color == Chip.BLACK) {
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| − | side = false;
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| − | } else {
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| − | side = true;
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| − | }
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| − | Alphamove winningmove = this.chooseMove(color, depth, alpha, beta, side, 10);
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| − | return winningmove.move;
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| − | }
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| − |
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| − | // simple method to generate the opponent's color
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| − | // given a color, @return the color of the opponent
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| − | public static int generateOpponent(int color) {
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| − | if (color == Chip.WHITE) {
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| − | return Chip.BLACK;
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| − | } else {
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| − | return Chip.WHITE;
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| − | }
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| − | }
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| − |
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| − | // evaluates the given network for a winning color
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| − | // returns a probability of winning if there is no win (positive for white advantage, negative for black advantage)
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| − | // returns WHITEWIN if WHITE wins, BLACKWIN if BLACK wins
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| − | // @return an int with this board's score
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| − | public int winner() {
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| − | {{notmine|Jordan Berk|fragment=yes}}
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| − | }
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| − |
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| − | // helper function for winner - recursively finds networks and assigns 1 point per connection and 10000 for a win
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| − | // @return an int with the score of the network
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| − | int findNetwork(Gameboard g, int x, int y, int color, int num, String currentDirection, String lastDirection) {
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| − | {{notmine|Jordan Berk|fragment=yes}}
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| − | }
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| − |
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| − | // debugging method to print a gameboard
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| − | // @return a string represeting the board
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| − | public String toString() {
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| − | String output = "\n|";
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| − | for (y=0; y<DIMENSION; y++) {
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| − | for (x=0; x<DIMENSION; x++) {
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| − | if (board[x][y] == null) {
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| − | output = output + " .";
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| − | } else {
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| − | output = output + " " + ((Chip) board[x][y]).getColor();
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| − | }
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| − | }
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| − | output = output + "|\n|";
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| − | }
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| − | return output;
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| − | }
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| − | }
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