im currently programming a sudoku game in java. I created a 2 dimensional array as the playingfield. Now i want to write a method, which saves numbers for a given position in the playingfield, for example i want to save the numbers 9 and 4 at the position (3,5) in the field. I've thought about to create an array for the position and save the numbers there, i've tried that but i really dont know how to do it. I searched some sites for my problem but i couldnt find solution for it. I hope someone can help me with that.
public byte[][] sudoku = new byte[9][9];
public SudokuField(byte[][] sudoku){
if(sudoku.length != 9){
System.exit(2);
}
for(int i = 0; i < sudoku.length; i++){
if(sudoku[i].length > 9){
System.exit(2);
}
}
this.sudoku = sudoku;
}
public boolean checkColumn(int x, int y, byte value){
boolean check = true;
for(int i = 0; i < this.sudoku.length; i++){
if(this.sudoku[i][y] == value){
check = false;
}
}
return check;
}
public boolean checkRow(int x, int y, byte value){
boolean check = true;
for(int i = x; i < x + 1; i++){
for(int j = 0; j < this.sudoku[i].length; j++){
if(this.sudoku[i][j] == value){
check = false;
}
}
}
return check;
}
public boolean checkSquare(int x, int y, byte value){
boolean check = true;
x = (int)(x / 3) * 3;
y = (int)(y / 3) * 3;
for(int i = x; i < x + 3; i++){
for(int j = y; j < y + 3; j++){
if(this.sudoku[i][j] == value){
check = false;
}
}
}
return check;
}
public void setCell(int x, int y, byte value){
if(x < 0 || x > 9 || y < 0 || y > 9){
System.out.println("Invalid Number");
}else if(checkRow(x,y, value) && checkColumn(x,y,value) && checkSquare(x, y, value)){
this.sudoku[x][y] = value;
}else{
System.out.println("Invalid cell");
}
}
public byte getCell(int x, int y){
return this.sudoku[x][y];
}
public void markCell(int x, int y, byte value){
}
So this is the code i wrote so far. Im currently working on markCell, which saves numbers at a position u might want to put into the position. So my idea is to create an array for the position, to store these numbers in it.
Related
I have this class that randomly creates rooms next to each other, and prints brackets (which represent the rooms) to the console. But I wanted to know how to add something like that to a JPanel for a GUI. Here is the room generator class:
public class Rooms {
static final int width = 15, height = 10;
static final int rooms = 19;
static boolean[][] room = new boolean[width][height];
static int neighborCount(int x, int y) {
int n = 0;
if (x > 0 && room[x-1][y]) n++;
if (y > 0 && room[x][y-1]) n++;
if (x < width-1 && room[x+1][y]) n++;
if (y < height-1 && room[x][y+1]) n++;
return n;
}
public void Rooms() {
room[width/2][height/2] = true;
Random r = new Random();
int x, y, nc;
for (int i = 0; i < rooms; i++) {
while (true) {
x = r.nextInt(width);
y = r.nextInt(height);
nc = neighborCount(x, y);
if (!room[x][y] && nc == 1) break;
}
room[x][y] = true;
}
for (y = 0; y < height; y++) {
for (x = 0; x < width; x++)
System.out.print(room[x][y] ? "[]" : " ");
System.out.print();
}
}
}
Thanks for the help!
You probably want to use java.awt.Graphics. It lets you draw primitive shapes like lines, rectangles, circles, etc. This might get you started. Section 2 also covers how to draw on a JPanel.
This question already has answers here:
How do I do a deep copy of a 2d array in Java?
(7 answers)
Closed 8 years ago.
So I am trying to make an algorithm for finding full paths in NxN grid. For example in 1x1 grid there is 1 possible path, in 2x2 grid there is 1, in 3x3 there is 2 and in 4x4 there is 8. The idea is to find scenarios where we can fill every spot of the grid by moving.
I have made a recursive function for the job and here is the code:
public static int getRoutesHelp(int[][] table, int x, int y)
{
if(x > table.length-1 || x < 0 || y < 0 || y > table.length-1)
return 0;
if(table[x][y] == 1)
return 0;
table[x][y] = 1;
if(isDeadEnd(table, x, y))
{
if(isTableFull(table))
return 1;
}
else
{
int a = getRoutesHelp(table, x-1, y);
int d = getRoutesHelp(table, x, y+1);
int b = getRoutesHelp(table, x+1, y);
int c = getRoutesHelp(table, x, y-1);
return a+b+c+d;
}
return 0;
}
public static int getRoutes(int size)
{
int[][] table = new int[size][size];
// init table
for(int i = 0; i < size; i++)
{
for(int a = 0; a < size; a++)
{
table[i][a] = 0;
}
}
return getRoutesHelp(table, 0 ,0);
}
So basically I start from 0.0 and start moving to all possible directions and by repeating this I get the amount of successful routes. The problem is that after the assignment of int d the original table is somehow filled with 1 but it should be empty as far as I understand because java passes a copy of the table right? I've been fighting with this for like 4 hours and can't really find the problem so any help is appreciated. Empty slots in table are marked with 0 and filled slots with 1.
EDIT: I managed to fix the issue I had with the copying and now my other problem is that with 5x5 grid my algorithm returns 52 routes and it should be 86. So it works with 4x4 grid okay, but once I move further it breaks.
Added the isDeadEnd function here
public static boolean isDeadEnd(int[][] table, int x, int y)
{
int toCheck[] = new int[4];
toCheck[0] = x-1; // left
toCheck[1] = y-1; // top
toCheck[2] = x+1; // right
toCheck[3] = y+1; // bottom
int valuesOfDirections[] = new int[4]; // left, top, right, bottom
for(int i = 0; i < 4; i++)
{
int tarkastettava = toCheck[i];
if(tarkastettava > table.length-1 || tarkastettava < 0)
{
valuesOfDirections[i] = 1;
}
else
{
if(i == 0 || i == 2)
{
valuesOfDirections[i] = table[tarkastettava][y];
}
else
{
valuesOfDirections[i] = table[x][tarkastettava];
}
}
}
for(int i = 0; i < 4; i++)
{
if(valuesOfDirections[i] == 0)
{
return false;
}
}
return true;
}
Come to think of it, you probably can do a simple backtrack here:
table[x][y] = 1;
if(isDeadEnd(table, x, y)) {
if(isTableFull(table))
return 1;
}
table[x][y] = 0;
}
And later:
int res = a + b + c + d;
if (res == 0) {
// backtrack here too
table[x][y] = 0;
}
return res;
im creating a code for Minesweeper and trying to implement a GUI. But the problem is that when i run the code and play the game, the position i click on the board reveals the y,x coordinate of that location on the answer board rather than the x, y coordinate. Ive been trying to fix this but i cant see to figure it out. i think it maybe is the way i create the board, but i tried everything i could think of.
class Board{
public MsGUI gui;
private static char[][] userBoard;
private static char[][] solutionBoard;
private static int boundSize = 5;
public Board(){
userBoard = new char[][] {{'-','-','-','-','-'},
{'-','-','-','-','-'},
{'-','-','-','-','-'},
{'-','-','-','-','-'},
{'-','-','-','-','-'}};
solutionBoard = new char[][] {{'0','2','B','2','0'},
{'0','3','B','3','0'},
{'1','3','B','3','1'},
{'B','1','3','B','2'},
{'1','1','2','B','2'}};
return;
}
private static void printBoard(char[][] board){
for (int x = 0; x < boundSize; x++){
for(int y = 0; y < boundSize; y++){
System.out.print(" " + Character.toString(board[x][y]));
}
System.out.println("");
}
System.out.println("");
}
public void flagCell(int xCoordinate, int yCoordinate){
userBoard[xCoordinate][yCoordinate] = 'F';
}
public boolean isFlagged(int xCoordinate,int yCoordinate){
if(userBoard[xCoordinate][yCoordinate] == 'F'){
return true;
}
else{
return false;
}
}
public int getHeight() {
return userBoard.length;
}
public int getWidth(){
return userBoard[0].length;
}
public char getValue(int xCoordinate, int yCoordinate) {
return userBoard[xCoordinate][yCoordinate];
}
private static boolean checkIfAlreadyMarked(int xCoordinate, int yCoordinate)
{
boolean marked = false;
if (Character.toString(userBoard[xCoordinate][yCoordinate]).equals("-") == false)
{
marked = true;
}
return marked;
}
public void revealCell(int xCoordinate, int yCoordinate){
int count = 0;
for(int i = 0;i < userBoard.length;i++){
for(int J = 0;J < userBoard[i].length;J++){
if(userBoard[i][J] != '-'){
count = count + 1;
}
}
if(count == 19){
gui.win("you won");
return;
}
}
if(solutionBoard[xCoordinate][yCoordinate] == 'B'){
userBoard[xCoordinate][yCoordinate] = solutionBoard[xCoordinate][yCoordinate];
gui.lose("You lost. Better luck next time!");
return;
}
if(solutionBoard[xCoordinate][yCoordinate] != '0'){
userBoard[xCoordinate][yCoordinate] = solutionBoard[xCoordinate][yCoordinate];
}else{
userBoard[xCoordinate][yCoordinate] = solutionBoard[xCoordinate][yCoordinate];
for(int i = 1; i > -2; i--){
if(xCoordinate-i >= solutionBoard.length || xCoordinate-i < 0)
continue;
for(int z = 1; z > -2; z--){
if(yCoordinate-z >= solutionBoard[xCoordinate].length || yCoordinate-z < 0)
continue;
else if(userBoard[xCoordinate-i][yCoordinate-z] == 'F' || userBoard[xCoordinate-i][yCoordinate-z] != '-')
continue;
else{
revealCell(xCoordinate-i, yCoordinate-z);
}
}
}
}
}
public void unflagCell(int xCoordinate, int yCoordinate){
userBoard[xCoordinate][yCoordinate]='-';
}
public static void main(String[] args){
Board b = new Board();
b.gui = new MsGUI(b);
b.gui.setVisible(true);
}
}
The way you are initializing the solutionBoard is not what you expect it to be.
If you get solutionBoard[0], you're not accessing the first column(which would be consistent with what I think is your understanding), but the first row(first item of the two-dimensional array): {'0','2','B','2','0'}
So if you want to have x for a row index and y for a column index and still keep this "readable" initialization, you'll have to swap the indices whenever you access the array.
But this will only help you with one problem - human readable array assignment in the beginning, but I think you'll regret this decision in the future.
EDIT:
You can have the array initialized as you want and still use readable format like this:
String readableBoard =
"0 2 B 2 0;" +
"0 3 B 3 0;" +
"1 3 B 3 1;" +
"B 1 B B 2;" +
"1 1 2 B 2";
char[][] board = initBoard(readableBoard);
....
private char[][] initBoard(String readableBoard){
char[][] board = new char[5][5];
String[] rows = readableBoard.split(";");
String[] fields = null;
for (int y = 0; y<rows.length;y++){
fields = rows[y].split(" ");
for (int x = 0; x<fields.length; x++){
board[x][y]=fields[x].charAt(0);
}
}
return board;
}
Now when you call
board[2][0]
You'll get 'B'
If you look at your nested for loops, you're printing off the columns instead of what I assume to be the desired rows. Try switching your for loops to iterate over y, then x.
for (int y = 0; y < boundSize; y++){
for(int x = 0; x < boundSize; x++){
System.out.print(" " + Character.toString(board[x][y]));
}
System.out.println("");
}
System.out.println("");
i'm a bit stuck with the Sudoku algorithm, i coded it using backtrack, and following the theorical steps this should work, and i tried to debuge it, but is too hard (and yes, it solve some numbers and does things)
i paste the code, i hope that you can help me, i really can't see where the problem is...
public void backtracking(int row,int col){
if(row > 8){
System.out.println("Solution Found!!");
printSudoku();
}
if (m[row][col] != 0){
next(row, col);
}
else {
for(int i =1; i < n;i++)
if(row(row, i) && col(col, i)) {
m[row][col] =i;
next(row, col);
}
m[row][col] = 0;
}
}
public void next( int row, int col ) {
if( col < 8)
backtracking( row, col + 1 ) ;
else
backtracking( row+ 1, 0 ) ;
}
public boolean region(int x, int y, int numReg) {
x = (x / 3) * 3 ;
y = (y / 3) * 3 ;
for( int r = 0; r < 3; r++ )
for( int c = 0; c < 3; c++ )
if( m[x+r][y+c] == numReg )
return false ;
return true ;
}
public boolean row(int x, int k){
for(int i =0; i < 9; i++)
if(m[x][i] == k)
return false;
return true;
}
public boolean col(int x, int k){
for(int i =0; i < 9; i++)
if(m[i][x] == k)
return false;
return true;
}
I ommited the "printSudoku" method, is just a double for and you know.
The code seems almost right.
As far as i can see you just forgot to call the region method. And I can't see where the variable n is coming from.
Try it with this slightly modified backtracking method:
public static void backtracking(int row, int col) {
if (row > 8) {
System.out.println("Solution Found!!");
printSudoku();
System.exit(0); //exiting after solution is found
}
if (m[row][col] != 0) {
next(row, col);
} else {
for (int i = 1; i <= 9; i++) //replaced i < n with i<=9
if (row(row, i) && col(col, i) && region(row, col, i)) { //calling region method too
m[row][col] = i;
next(row, col);
}
m[row][col] = 0;
}
}
code:
Array is a predefined boolean array that I made, and val is the length of the array (it is a square). I use it as a starting point, rather than using a random value
import java.util.*;
import javax.swing.*;
public class Main
{
public void main()
{
String Val = JOptionPane.showInputDialog("Enter the number of rows/columns");
int x = Integer.parseInt(Val);
boolean mazeArch[][] = new boolean [x][x];
BoundariesDeclared(mazeArch, x);
generateMaze(mazeArch, x);
convertArray(mazeArch, x);
}
public void printArray(String Array[][]) // Prints out the array
{
for (int i =0; i < Array.length; i++) {
for (int j = 0; j < Array.length; j++) {
System.out.print(" " + Array[i][j]);
}
System.out.println("");
}
}
public void convertArray(boolean Array[][], int z)
{
String RealArray[][] = new String [z][z];
for(int x = 0; x < Array.length; x++)
{
for(int y = 0; y < Array.length; y++)
{
if(Array[x][y] == true)
{
RealArray[x][y] = "*";
}
if(Array[x][y] == false)
{
RealArray[x][y] = " ";
}
}
}
printArray(RealArray);
}
public void BoundariesDeclared(boolean Array[][], int y)
{
for(int x = 0; x < Array.length; x++)
Array[0][x] = true;
for (int x = 0; x < Array.length; x++)
Array[x][0] = true;
for (int x = 0; x < Array.length; x++)
Array[x][Array.length-1] = true;
for (int x = 0; x < Array.length; x++)
Array[Array.length-1][x] = true;
}
public void generateMaze(boolean Array[][], int val)
{
Stack<Integer> StackX = new Stack<Integer>();
Stack<Integer> StackY = new Stack<Integer>();
int x = val / 2; // Start in the middle
int y = val / 2; // Start in the middle
StackX.push(x);
StackY.push(y);
while(!StackX.isEmpty())
{
Array[x][y] = true; // is Visited
x = StackX.peek();
y = StackY.peek();
if(Array[x][y+1] == false)
{
StackX.push(x);
StackY.push(y+1);
y = y + 1;
}
else if(Array[x][y-1] == false)
{
StackX.push(x);
StackY.push(y-1);
y = y - 1;
}
else if(Array[x+1][y] == false)
{
StackX.push(x+1);
StackY.push(y);
x = x+1;
}
else if(Array[x-1][y] == false)
{
StackX.push(x-1);
StackY.push(y);
x = x-1;
}
else
{
StackX.pop();
StackY.pop();
}
}
}
}
Whenever I print the results, I only get stars, which mean that every single boolean is set to true. I understand my error, because I am visiting every spot the result will be that they are all set to true. But what can i do to fix this? I think I have the concept correct, just not the application. I previously asked the question and was told that I need to make two Arrays (1 for walls, another for visiting) but how would I apply this as well?
You didn't mention what are you trying to do. So not much we can help.
What is this maze doing?
What's your input?
What's your expected result?
Add this line and debug yourself.
public void generateMaze(boolean Array[][], int val) {
Stack<Integer> StackX = new Stack<Integer>();
Stack<Integer> StackY = new Stack<Integer>();
int x = val / 2; // Start in the middle
int y = val / 2; // Start in the middle
StackX.push(x);
StackY.push(y);
while (!StackX.isEmpty()) {
Array[x][y] = true; // is Visited
x = StackX.peek();
y = StackY.peek();
if (Array[x][y + 1] == false) {
StackX.push(x);
StackY.push(y + 1);
y = y + 1;
} else if (Array[x][y - 1] == false) {
StackX.push(x);
StackY.push(y - 1);
y = y - 1;
} else if (Array[x + 1][y] == false) {
StackX.push(x + 1);
StackY.push(y);
x = x + 1;
} else if (Array[x - 1][y] == false) {
StackX.push(x - 1);
StackY.push(y);
x = x - 1;
} else {
StackX.pop();
StackY.pop();
}
convertArray(Array, val); // add this line
}
}
The solution is still the same as when you last posted this question - you need to have two arrays
-one that is true for every place in the maze that is a wall - the maze's tiles
-one that starts all false - the solver's tiles
The solver can move onto a tile only if both arrays are false at that point, and sets the second array (the solver's tiles) to true while leaving the first array (the maze's tiles) alone.
This is not a 'coding' bug, per say. You simply don't know what behavior you want. Try commenting out the line where you generate the maze. Run your program with 6 as a parameter. You get:
* * * * * *
* *
* *
* *
* *
* * * * * *
What kind of maze is this? Where is the exit? Again, this is not a coding issue, this is a design flaw. Of course if you start within the bounds of this maze, you will visit all of the squares!
I'm not clear what do you expect in your output exactly, but I can see where the issue is. In your generateMaze() method you are travelling like in spiral mode which ends up touching each and every node in the end. Like suppose you have 5x5 array, you travel and make true like (boundaries are already true) [2,2]->[2,3]->[3,3]->[3,2]->[3,1]->[2,1]->[1,1]->[1,2]->[1,3]
you start from middle, you start visiting and take turns just before you find already true (boundary or visited), and it covers all the nodes