Thread: Chess Problem

Hi, im pretty new to programming, and I am struggling with my current project.

This class is supposed to imitate a Queen piece from a chess board. I take its position (int row, int column ) and I must make an isValid method that will return whether or not the piece can move from its current position to a new given position that is brought into the isValid method through its parameters. What I have so far covers the rows and columns, but I can not figure out how to validate the diagonals.

Here is the code:

public class Queen {
// declare needed variables
private int queenRow;
private int queenColumn;
private String name = "Queen";
private boolean valid;

public Queen(int queenRow, int queenColumn, String name) {

this.queenRow = queenRow;
this.queenColumn = queenColumn;
this.name = name;

}

// method to set the Queen's position
public void setQueenPos(int queenRow, int queenColumn) {
this.queenRow = queenRow;
this.queenColumn = queenColumn;
}

public void moveQueen(int i, int j) {

if (valid == true) {
this.queenRow = i;
this.queenColumn = j;
} else {
System.out.println("The queen cannot move there.");
}

}

// method to validate the piece's move
public boolean isValid(int row, int column) {

if (row == this.queenRow && column <= 8 && column > 0) {
valid = true;
} else if (column == this.queenColumn && row <= 8 && row > 0) {
valid = true;
}

return valid;
}

// method to return the Queen's position
public int getQueenRow() {
return queenRow;

}

public int getQueenColumn() {
return queenColumn;
}

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

public static void main(String[] args) {
Queen obj = new Queen(1, 1, "Queen");

System.out.println(obj.getQueenRow() + " " + obj.getQueenColumn());
obj.isValid(1, 5);
obj.moveQueen(1, 5);
System.out.println(obj.getQueenRow() + " " + obj.getQueenColumn());
}

}

Basically, to get to a diagonal from a square, you have to move up by a certain number, then across by the same number

You need to think about the relation between the row and column value of the square its on and the row and column values of the diagonals. So if the queen is on row 4 column 6:
(4,6) then some of the diagonals are:
(5,5)
(7,3)
(6,8)
The difference between the row of the diagonal and the starting square and the difference between the column of the diagonal and the starting square are the same.

Also, can you put [ highlight=Java] and [ /highlight] tags round your code, makes it easier to read, cheers

Thanks a lot, that is all very helpful and I will be sure to put the highlight around it next time.