2048

-- created by coolsa. ver 1.4
-- pastebin is a bit different, but thats ok.
local function win(area)
	can=false
	for a=1,4 do
		for b=1,4 do
			if area[a][b]>=11 then
				can=true
			end
		end
	end
	return can
end
local function drawPix( xPos, yPos )
term.setCursorPos(xPos, yPos)
term.write(" ")
end
local function compr(old,new)
	c=0
	for a=1,4 do
		for b=1,4 do
			if old[a][b]==new[a][b] then
				c=c+1
			end
		end
	end
	if c==16 then return true else return false end
end
local function cln(cln)
	c={}
	for a=1,4 do
		c[a]={}
		for b=1,4 do
			c[a][b]=cln[a][b]
		end
	end
	return c
end
local function randVal()
	if(math.random(10)%10==0) then
		return 2
	else
		return 1
	end
end
local function randTile(area)
	i=0
	while true do
		x=math.random(4)
		y=math.random(4)
		val=randVal()
		if area[x][y]==0 then
			break
		elseif area[x][y]~=0 then
			i=i+1
		end
		if i>=101 then
			break
		end
	end
	if i>=100 then
		x,y,val=0,0,"nope"
	end
	return x,y,val
end
function board()
	board={}
	for a=0,5 do
		board[a]={}
		for b=0,5 do
			board[a][b]=0
		end
	end
	return board
end
--move up -> check down -> move up
function meldUp(ar)
	for c=1,3 do
		for a=1,4 do
			for b=3,1,-1 do
				if ar[a][b]==0 then
					ar[a][b]=ar[a][b+1]
					ar[a][b+1]=0
				end
			end
		end
	end
	for a=1,4 do
		for b=1,3 do
			if (ar[a][b]>0 and ar[a][b]==ar[a][b+1]) then
				ar[a][b]=ar[a][b]+1
				ar[a][b+1]=0
			end
		end
	end
	for c=1,3 do
		for a=1,4 do
			for b=3,1,-1 do
				if ar[a][b]==0 then
					ar[a][b]=ar[a][b+1]
					ar[a][b+1]=0
				end
			end
		end
	end
	return ar
end
function meldDown(ar)
	for c=1,3 do
		for a=1,4 do
			for b=1,3 do
				if ar[a][b+1]==0 then
					ar[a][b+1]=ar[a][b]
					ar[a][b]=0
				end
			end
		end
	end
	for a=1,4 do
		for b=3,1,-1 do
			if (ar[a][b]>0 and ar[a][b]==ar[a][b+1]) then
				ar[a][b+1]=ar[a][b+1]+1
				ar[a][b]=0
			end
		end
	end
	for c=1,3 do
		for a=1,4 do
			for b=1,3 do
				if ar[a][b+1]==0 then
					ar[a][b+1]=ar[a][b]
					ar[a][b]=0
				end
			end
		end
	end
	return ar
end
function meldRight(ar)
	for c=1,3 do
		for a=1,4 do
			for b=3,1,-1 do
				if ar[b][a]==0 then
					ar[b][a]=ar[b+1][a]
					ar[b+1][a]=0
				end
			end
		end
	end
	for a=1,4 do
		for b=1,3 do
			if (ar[b][a]>0 and ar[b][a]==ar[b+1][a]) then
				ar[b][a]=ar[b][a]+1
				ar[b+1][a]=0
			end
		end
	end
	for c=1,3 do
		for a=1,4 do
			for b=3,1,-1 do
				if ar[b][a]==0 then
					ar[b][a]=ar[b+1][a]
					ar[b+1][a]=0
				end
			end
		end
	end
	return ar
end
function meldLeft(ar)
	for c=1,3 do
		for a=1,4 do
			for b=1,3 do
				if ar[b+1][a]==0 then
					ar[b+1][a]=ar[b][a]
					ar[b][a]=0
				end
			end
		end
	end
	for a=1,4 do
		for b=3,1,-1 do
			if (ar[b][a]>0 and ar[b][a]==ar[b+1][a]) then
				ar[b+1][a]=ar[b+1][a]+1
				ar[b][a]=0
			end
		end
	end
	for c=1,3 do
		for a=1,4 do
			for b=1,3 do
				if ar[b+1][a]==0 then
					ar[b+1][a]=ar[b][a]
					ar[b][a]=0
				end
			end
		end
	end
	return ar
end
board=board()
for i=1,2 do
	a,b,val=randTile(board)
	board[a][b]=val
end
while true do
	oboard=cln(board)
	local event,pra=os.pullEvent()
	term.clear()
	if pra==14 then
		break
	elseif pra==200 then
		board=meldUp(board)
	elseif pra==205 then
		board=meldLeft(board)
	elseif pra==203 then
		board=meldRight(board)
	elseif pra==208 then
		board=meldDown(board)
	end
  
	if compr(oboard,board)==false then
	   a,b,val=randTile(board)
	   board[a][b]=val
	end
	for y=1,4 do
		for x=1,4 do
			term.setCursorPos(x*5-3,y*4-2)
			if board[x][y]==0 then
				term.write("	 ")
			else
				term.write(2^board[x][y])
			end
		end
	end
	if win(board) then
		term.setCursorPos(1,16)
		term.write("you win!")
	end
end
term.setCursorPos(1,1)
--backspace = 14 exit.
--up = 200	   1
--left 203	   2
--right 205	  3
--down = 208	 4