Sudoku Puzzle Generator/Sovler

----------------------------------------------MISC FUNCS
function logBoard(board, currentPos)
    for y = 1, 9 do
    term.setCursorPos(1, y + math.ceil(y/3) - 1)
        for x = 1, 9 do
            if tonumber(board[y][x]) then
                term.setTextColor(colors.red)
                write(board[y][x])
            else
                term.setTextColor(colors.white)
                write("0")
            end
            if x == 3 or x == 6 then
                write(" ")
            end
        end
    end
    if currentPos then
        term.setTextColor(colors.orange)
        term.setCursorPos(currentPos[2] + math.floor((currentPos[2]-1)/3), currentPos[1] + math.floor((currentPos[1]-1)/3))
        term.write("*")
    end
    print("")
end

function printBoard(board)
    local c = 0
    for y = 1, 13 do
        term.setCursorPos(1, y)
        if y == 5 or y == 9 then
            term.write("|---+---+---|")
            c = c + 1
        elseif y == 1 or y == 13 then
            term.write("=============")
            c = c + 1
        else
            term.write("|")
            for x = 1, 9 do
                if tonumber(board[y-c][x]) then
                    term.setTextColor(colors.red)
                    write(board[y-c][x])
                else
                    term.setTextColor(colors.white)
                    write("0")
                end
                if x == 3 or x == 6 then
                    write("|")
                end
            end
            term.write("|")
        end
    end
    term.setCursorPos(1, 13)
    term.write(interString)
    print("")
end

----------------------------------------------GENERATION
function initializeBoard(board)
    for y = 1, 9 do
        board[y] = {}
        for x = 1, 9 do
            board[y][x] = {1, 2, 3, 4, 5, 6, 7, 8, 9}
        end
    end
end

function generatePuzzle(board)
    cellsLeft = {}
    for i = 1, 81 do
        cellsLeft[i] = i
    end
    while #cellsLeft > 0 do
        currentCell = table.remove(cellsLeft, math.random(1, #cellsLeft))
        currentCell = {math.ceil(currentCell/9), (currentCell-1)%9 + 1}    --y, x
        chooseCellNum(currentCell, board)
    end
end

function chooseCellNum(cell, board)
    --print(cell[1] .. " " .. cell[2])
    printBoard(board, cell)
    local numsDetected = {}
    for i = 1, 9 do
        if tonumber(board[cell[1]][i]) then
            table.insert(numsDetected, board[cell[1]][i])
        end                                     --scan rows/columns for pre-existing numbers
        if tonumber(board[i][cell[2]]) then
            table.insert(numsDetected, board[i][cell[2]])
        end
    end
    for y = 1 + (math.ceil(cell[1]/3)-1)*3, 3 + (math.ceil(cell[1]/3)-1)*3 do  --scan the surrounding box
        for x = 1 + (math.ceil(cell[2]/3)-1)*3, 3 + (math.ceil(cell[2]/3)-1)*3 do
            --print (y .. " " .. x)
            if tonumber(board[y][x]) then
                table.insert(numsDetected, board[y][x])
            end
        end
    end
    table.sort(numsDetected)
    for i = #numsDetected, 2, -1 do
        if numsDetected[i] == numsDetected[i-1] then
            table.remove(numsDetected, i)   --ensure each element occurs only once
        end
    end
    local possibleNums = {}
    local index = 1
    for i = 1, 9 do
        if numsDetected[index] ~= i then
            table.insert(possibleNums, i)
        else
            index = index + 1
        end
    end
    sleep(.2)
    if #possibleNums == 0 then
        term.setBackgroundColor(colors.black)
        term.setTextColor(colors.white)
        printBoard(board, cell)
        --print(cell[1] .. ":" .. cell[2])
        term.setCursorPos(1, 12)
    end
    local result = possibleNums[math.random(1, #possibleNums)]
    board[cell[1]][cell[2]] = result  --choose one of the renaiming possible nums
end

----------------------------------------------SOLUTION

----------------------------------------------ENGINE
local tArgs = {...}
term.setBackgroundColor(colors.black)
term.setTextColor(colors.white)
term.clear()

if tArgs[1] == "generate" or tArgs[1] == "gen" then
    local board = {}
    initializeBoard(board)
    printBoard(board)
    generatePuzzle(board)
    printBoard(board)
elseif tArgs[1] == "solve" then

end