Tetris  2


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Functionality:			80
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the height[] widths and maxheight are update properly  10 
	basically the top/horizon line should appear green in JBoardTEst

place()					10

	This takes a piece, and an (x,y), and sets the piece into the grid
	with the origin (the lower-left corner) of the piece at that
	location in the board. The undo() operation (below) can remove the
	most recently placed piece.  Return value: returns PLACE_OK for a
	successful placement. Returns PLACE_ROW_FILLED for a successful
	placement that also caused at least one row to become filled.


clearRows()				20

	This method deletes each row that is filled all the way across,
	causing things above to shift down. New rows shifted in at the top
	of the board should be empty. There may be multiple filled rows,
	and they may not be adjacent.  The perfect solution does
	everything in one pass.

	update heights[]. update widths[]. update maxHeight
		
dropHeight()			20

	computes the y value where the origin (0,0) of a piece will come
	to rest if dropped in the given column from infinitely high. Drop
	height should use the heights[] array and the skirt of the piece
	to compute the y value quickly, in O(piece-width)
	time. DropHeight() assumes the piece falls straight down -- it
	does not account for moving the piece around things during the
	drop.

the Undo mechanism		20

	place() and clearRows() operations copy the main state to the
	backup before making changes: that is, copies the board, widths[]
	and heights[]. The simplest strategy is to just backup all the
	columns when place() happens. This is an acceptable strategy. In
	this case, no further backup is required for clearRows(), since
	place() already backed up the whole grid.

	undo() restores the main state from the backup: swat the backup
	and the main states.



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Style and structure:	20
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easy to read and understand and verify overall correctness of the
underlying logic. Did not modify any otehr function to get things to
work 

sanityCheck() needs to be implemented and used for debugging (points
will not be taken off for this only in the case the program works
perfectly)