ComputerCraft Game of Life

-- ComputerCraft Game of Life
-- For 8x5 advanced monitor
-- By Numerical (youtube/jreflex93)

w = 41
h = 33

grid = {}
for ih = 1, h do
    grid[ih] = {}
    for iw = 1, w do
        rand = math.random(0, 99)
        if(rand < 10)
            then grid[ih][iw] = true
            else grid[ih][iw] = false
        end
    end
end
gridNext = {}
for ih = 1, h do
    gridNext[ih] = {}
    for iw = 1, w do
        gridNext[ih][iw] = false
    end
end

function printGrid()
    term.clear()
    for ih = 1, h do
        for iw = 1, w do
            term.setCursorPos((iw+iw-1), ih)
            if(grid[ih][iw]) then
                term.setTextColor(colors.lime) else
                term.setTextColor(colors.black)
            end
            term.write("@ ")
        end
    end
end

function calcNext()
    for ih = 1, h do
        for iw = 1, w do
            n = 0
            if(iw~=w and grid[ih][iw+1]) then n = n + 1 end -- right
            if(iw~=1 and grid[ih][iw-1]) then n = n + 1 end -- left
            if(ih~=h and grid[ih+1][iw]) then n = n + 1 end -- down
            if(ih~=1 and grid[ih-1][iw]) then n = n + 1 end -- up
            if(ih~=1 and iw~=1 and grid[ih-1][iw-1]) then n = n + 1 end -- up left
            if(ih~=1 and iw~=w and grid[ih-1][iw+1]) then n = n + 1 end -- up right
            if(ih~=h and iw~=1 and grid[ih+1][iw-1]) then n = n + 1 end -- down left
            if(ih~=h and iw~=w and grid[ih+1][iw+1]) then n = n + 1 end -- down right
            if(n == 3 or (n == 2 and grid[ih][iw]))
                then gridNext[ih][iw] = true
                else gridNext[ih][iw] = false
            end
        end
    end
end

function setNext()
    for ih = 1, h do
        for iw = 1, w do
            grid[ih][iw] = gridNext[ih][iw]
        end
    end
end

term.clear()
term.setCursorPos(35,31)
term.setTextColor(colors.yellow)
term.setBackgroundColor(colors.black)
sleep(0.5)
term.write("3... ")
sleep(1)
term.write("2... ")
sleep(1)
term.write("1... ")
sleep(1)


while(true) do
    calcNext()
    setNext()
    printGrid()
    sleep(0.1)
end