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Well I've been working on a Sudoku Solver. I ran into a problem;
This is a typical Sudoku:

So here's my problem;
In my code, the way I'm doing it is I have 81 instances of a "cell" class, representing one of the possible values on the Sudoku.
However, for a given row ex:
1 2 3 4 5 6 7 8 9
I have an array of cells;
0 1 2 3 4 5 6 7 8 would be my first row
9 10 11 12 13 14 15 16 17would be my second row.

So I need a clever way to add cells to each appropriate "box"
so for box one, the numbers in the box would be 0 1 2 from the first row, 9 10 11 from the second row.
Box two would be 4 5 6 from the first row, and 12 13 14 from the second etc etc
Anyone have any ideas?

I'd use a 9*9 2D array of integers

`int[][] sodoku = new int[9][9];`

Then you don't need to create a Cell class, or have to do any math to get the location of a Cell.

=S, well the way I programmed it... gah.
Here are my files. I already have a newboard or sudoku board two dimensional array.

```public class GetDataMethods {
int emptycells[];
int rows[]=new int[9];
int cols[]=new int[9];
int[][] newboard =
{{0,0,0,0,6,0,0,0,9},
{0,6,0,0,0,0,3,0,1},
{2,0,0,0,0,9,8,0,0},
{1,9,6,0,0,2,0,0,8},
{0,0,0,3,0,8,0,0,0},
{8,0,0,9,0,0,1,7,5},
{0,0,1,7,0,0,0,0,4},
{6,0,7,0,0,0,0,8,0},
{4,0,0,0,9,0,0,0,0}};
//	The Possible Values
public int possibilityboard[][];
int value;

public int[] getnumbersinrow(int row,int[][]board){

for(int y = 0; y<=8;y++){
rows[y]=newboard[row][y];
}

return rows;
}
public int getCell(int i, int j) {
return newboard[i][j];
}

public int[] getNeighbourhood(int i, int j) {
int left = (i/3)*3;
int top = (j/3)*3;
int[] neighbourhood = {getCell(left, top),
getCell(left, top+1),
getCell(left, top+2),
getCell(left+1, top),
getCell(left+1, top+1),
getCell(left+1, top+2),
getCell(left+2, top),
getCell(left+2, top+1),
getCell(left+2, top+2)};
return neighbourhood;
}
public int[] getnumbersincol(int col, int[][]board){
for(int z = 0; z<=8; z++){
cols[z]=newboard[z][col];
}
return cols;
}
public boolean isinrow(int number, int col){
for(int x = 0;x<=8;x++){
if(newboard[col][x]==number){
return true;

}
}
return false;
}
public int amountofcellsleft(){
int emptycount = 0;
for(int x = 0; x<=8;x++){
for(int y = 0; y<=8;y++){
if(newboard[x][y]==0){
emptycount++;
}
}
}
return emptycount;

}

public boolean isincol(int number, int row){
for(int x =0;x<=8;x++){
if(newboard[row][x]==number){
return true;
}
}
return false;
}
// Checks if a value is equal to zero
//Takes an array and an int as arguments
public boolean isarrayzero(int array[],int cellinarray){
if(array[cellinarray]==0){
return true;
}
else{
return false;
}
}
}```
```public class runprogram {
boolean unsolved = false;
int copyofbox[];
int copyofrow[];
int copyofcol[];
int copytest[];
int emptycellcount = 0;
GetDataMethods one = new GetDataMethods();
Cell two = new Cell();

public static void main(String[] args) {
runprogram run = new runprogram();
run.findemptycells();
}

public void findemptycells(){
two.assignvaluesandloc();
for(int x = 0;x<=80;x++){
if(two.cellarray[x].value==0){
two.cellarray[x].isnull=true;
}
}
assignpossiblevalues();
}

public void assignpossiblevalues(){
evaluatandremovepossibilities();
}

public void evaluatandremovepossibilities(){
while(one.amountofcellsleft()>0){
for(int cell = 0; cell <=80;cell++){

copyofrow= one.getnumbersincol(two.cellarray[cell].xloc, one.newboard);
copyofcol= one.getnumbersinrow(two.cellarray[cell].yloc, one.newboard);
copyofbox= one.getNeighbourhood(two.cellarray[cell].xloc, two.cellarray[cell].yloc);

for(int x =0 ; x<=8; x++){
for(int p = 0; p<=8;p++){
if(two.cellarray[cell].possiblevalues[x]==copyofbox[p]){
two.cellarray[p].value=10;
}
}
for(int y = 0; y<=8;y++){

if(two.cellarray[cell].possiblevalues[x]==copyofrow[y]){
two.cellarray[cell].possiblevalues[x]=10;
two.cellarray[cell].reallength--;

}
if(two.cellarray[cell].possiblevalues[x]==copyofcol[y]){
two.cellarray[cell].possiblevalues[x]=10;
two.cellarray[cell].reallength--;

}
}

}

for(int p = 0; p<=80;p++){

if(two.cellarray[p].reallength==1){
one.newboard[two.cellarray[p].xloc][two.cellarray[p].yloc] = two.cellarray[p].value;
}
}
}

System.out.println(one.amountofcellsleft());

}
}```
```public class Cell {

boolean isnull=false;
int neighborhood;
int value = 0;
int xloc = 0;
int yloc = 0;
int[] possiblevalues = {1,2,3,4,5,6,7,8,9};
int reallength = 9;
Cell[] cellarray = new Cell[81];
int arraylistoffset;

//Assigns each cell the xloc, yloc, and the value.
//Populates the cellarray
public void assignvaluesandloc(){
int x = 0;
GetDataMethods g = new GetDataMethods();
int currentnumber = 0;
for (int row = 0; row <= 8; row++)
{
for(int col = 0; col <= 8; col++)
{
cellarray[x] = new Cell();
cellarray[x].value=g.newboard[row][col];
cellarray[x].xloc=col;
cellarray[x].yloc=row;
x++;

}
}
removepossiblenumber();
}
private void removepossiblenumber() {
for(int x = 0; x<=80;x++){
if(cellarray[x].value!=0)
{
cellarray[x].possiblevalues[value]=10;
cellarray[x].reallength--;
}
}
}
// returns the Cell.value for a given cell
public int getcellvalue(int cellnumber){
return cellarray[cellnumber].value;
}
}```