rygh4775
commented
5 years ago 
Closed rygh4775 closed 5 years ago
rygh4775
commented
5 years ago
GyuminLee
commented
5 years ago
public class Grid {
private boolean[][] grid;
private Ant ant = new Ant();
public Grid() {
grid = new boolean[1][1];
}
/*
* Copy old values into new array, with an offset/shift applied to the row and column
*/
private void copyWithShift(boolean[][] oldGrid, boolean[][] newGrid, int shiftRow, int shiftColumn) {
for(int r = 0; r < oldGrid.length; r++) {
for(int c = 0; c < oldGrid[0].length; c++) {
newGrid[r + shiftRow][c + shiftColumn] = oldGrid[r][c];
}
}
}
/*
* Ensure that the given position will fit on the array. If necessary, double
* the size of the matrix, copy the oldvalues over, and adjust the ant's
* position so that it's in a positive range.
*/
private void ensureFit(Position position) {
int shiftRow = 0;
int shiftColumn = 0;
//Calculate new number of rows
int numRows = grid.length;
if(position.row < 0) {
shiftRow = numRows;
numRows *= 2;
} else if (position.row >= numRows) {
numRows *= 2;
}
// Calcuate new number of columns
int numColumns = grid[0].length;
if(position.column < 0) {
shiftColumn = numColumns;
numColumns *= 2;
} else if(position.column >= numColumns) {
numColumns *= 2;
}
//Grow array, if necessary. Shift ant's position too
if(numRows != grid.length || numColumns != grid[0].length) {
boolean[][] newGrid = new boolean[numRows][numColumns];
copyWithShift(grid, newGrid, shiftRow, shiftColumn);
ant.adjustPosition(shiftRow, shiftColumn);
grid = newGrid;
}
}
/*
* Flip color of cells
*/
private void flip(Position position) {
int row = position.row;
int column = position.column;
grid[row][column] = grid[row][column] ? false : true;
}
/*
* Move ant.
*/
public void move() {
ant.turn(grid[ant.position.row][ant.position.column]);
flip(ant.position);
ant.move();
ensureFit(ant.position);
}
/*
* Print board
*/
public String toString() {
StringBuilder sb = new StringBuilder();
for(int r = 0; r < grid.length; r++) {
for(int c = 0; c < grid[0].length; c++) {
if(r == ant.position.row && c == ant.position.column) {
sb.append(ant.orientation);
} else if(grid[r][c]) {
sb.append("X");
} else {
sb.append("_");
}
}
sb.append("\n");
}
sb.append("Ant: " + ant.orientation + ". \n");
return sb.toString();
}
}
public class Ant {
public Position position = new Position(0,0);
public Orientation orientation = Orientation.right;
public void turn(boolean clockwise) {
orientation = orientation.getTurn(clockwise);
}
public void move() {
if(orientation == Orientation.left) {
position.column--;
} else if(orientation == Orientation.right) {
position.column++;
} else if(orientation == Orientation.up) {
position.row--;
} else if(orientation == Orientation.down) {
position.row++;
}
}
public void adjustPosition(int shiftRow, int shiftColumn) {
position.row += shiftRow;
position.column += shiftColumn;
}
}
public enum Orientation {
left, up, right, down;
public Orientation getTurn(boolean clockwise) {
if(this == left) {
return clockwise ? up : down;
} else if(this == up) {
return clockwise ? right : left;
} else if(this == right) {
return clockwise ? down : up;
} else { //down
return clockwise ? left : right;
}
}
@Override
public String toString() {
// TODO Auto-generated method stub
if(this == left) {
return "\u2190";
} else if(this == up) {
return "\u2191";
} else if(this == right) {
return "\u2192";
} else { //down
return "\u2193";
}
}
}
public class Position {
public int row;
public int column;
public Position(int row, int column) {
this.row = row;
this.column = column;
}
}public class Board {
private HashSet<Position> whites = new HashSet<Position>();
private Ant ant = new Ant();
private Position topLeftCorner = new Position(0, 0);
private Position bottomRightCorner = new Position(0,0);
public Board() {}
/*
* Move ant
*/
public void move() {
ant.turn(isWhite(ant.position)); // Turn
flip(ant.position);
ant.move();
ensureFit(ant.position);
}
/*
* Flip color of cells
*/
private void flip(Position position) {
if(whites.contains(position)) {
whites.remove(position);
} else {
whites.add(position.clone());
}
}
/*
* Grow grid by tracking the most top-left and bottom-right positions
*/
private void ensureFit(Position position) {
int row = position.row;
int column = position.column;
topLeftCorner.row = Math.min(topLeftCorner.row, row);
topLeftCorner.column = Math.min(topLeftCorner.column, column);
bottomRightCorner.row = Math.max(bottomRightCorner.row, row);
bottomRightCorner.column = Math.max(bottomRightCorner.column, column);
}
/*
* Check if cell is white
*/
public boolean isWhite(Position p) {
return whites.contains(p);
}
/*
* Check if cell is white
*/
public boolean isWhite(int row, int column) {
return whites.contains(new Position(row, column));
}
/*
* Print board
*/
public String toString() {
StringBuilder sb = new StringBuilder();
int rowMin = topLeftCorner.row;
int rowMax = bottomRightCorner.row;
int colMin = topLeftCorner.column;
int colMax = bottomRightCorner.column;
for(int r = rowMin; r <= rowMax; r++) {
for(int c = colMin; c <= colMax; c++) {
if(r == ant.position.row && c == ant.position.column) {
sb.append(ant.orientation);
} else if(isWhite(r, c)) {
sb.append("X");
} else {
sb.append("_");
}
}
sb.append("/n");
}
sb.append("Ant: " + ant.orientation +". \n");
return sb.toString();
}
}
public class Position {
public int row;
public int column;
public Position(int row, int column) {
this.row = row;
this.column = column;
}
@Override
public boolean equals(Object obj) {
if( obj instanceof Position) {
Position p = (Position) obj;
return p.row == row && p.column == column;
}
return false;
}
@Override
public int hashCode() {
/*
* There are many options for hash function...
*/
return (row*31) ^ column;
}
public Position clone() {
return new Position(row, column);
}
}
