This program will impletment the general Magic Squares problem with objects.
At least two classes will be required. A Cell class, and a MagicSquare class. Cell class is responsible for keeping track of what, if anything is in any one square that makes up the magicSquare. The MagicSquare class is responsible for correctly filling the all of the individual squares that make up the magic square.
You will need to look over the note on Java: 2D Arrays
Things to notice:
in the instruction for magic square constructor you are told to set this.size with size
notice that there are two variables size available to the constructor. One is a parameter the other is an instance variable of the class (aka an attribute). The this. after size forces Java to use the instance variable, while just size will use value of the parameter within the method.
HAS-A: attributes
value:int the number to display in the magic square
isOccupied: boolean is true when the number has been set, otherwise false
row:int the row of the cell in the magic square
col:int the column of the cell in the magic square
RESPONDS-TO: methods or actions
constructor, two parameters are required, the row and column the cell to indicate the position in the magic square.
Cell(int r,int c)
sets row to r
sets col to c
sets isOccupied to false
public boolean isOccupied()
returns the value isOccupied.
public void setValue(int n)
sets value to n
set isOccupied to true
public int getRow()
returns the row
pubic int gerCol()
returns the col
public String toString()
returns a string with length of 7. It will include the number followed by 2 spaces. Extra spaces will be added to the front to make a String with a length of 7
HAS-A: attributes
size:int the size of the magic square; must be odd
startNumber: int the starting number
increment:int the amount to add each time.
magicSq[][]:cells a 2-d array of Cells
RESPONDS-TO: methods or actions
constructor
MagicSquare(size, start, step)
You will need to ensure that the value of size is an odd number and that the size is 5 or larger.
this.size = (size/2)*2 +1; // ensure that the size is odd.
Why does this work?
initMagciSq()
creates a 2-D array of Cells of any given size,
creates a cell for each location in the magicSq
setMagicSquare()
Local variables required
currentCell:Cell
range:int
Logic:
helper methods for setMagicSquare()
nextValue(int x)
parameter required: the current position in the range.
returns the next value to put in the cell ( startNumber + increment *x)
nextCell(Cell current)
returns the next current cell
Local variables
r: int -- working field for the row
c: int -- working field for the col
Logic: