使用lua语言生成一个消消乐玩法的程序,具体需求:1.棋盘是7*7, 2.图案由四种。 3.初始图案填满棋盘，并且不能出现相邻3个一样图案的情况，即初始无法相除。4.一共只有30步。5.图案只能上下左右移动。6.消除后图案自由下落。7.每消除一个图案获得1积分

以下是使用Lua语言实现消消乐游戏的代码，具体实现方式为命令行界面，需要在终端上运行。

-- 初始化棋盘，填充随机的图案
local board = {}
local patterns = {"A", "B", "C", "D"}
math.randomseed(os.time())
for i = 1, 7 do
    board[i] = {}
    for j = 1, 7 do
        local pattern
        repeat
            pattern = patterns[math.random(1, 4)]
        until not ((i > 2 and board[i - 2][j] == pattern and board[i - 1][j] == pattern) or
                  (j > 2 and board[i][j - 2] == pattern and board[i][j - 1] == pattern))
        board[i][j] = pattern
    end
end

-- 打印当前棋盘
function print_board(board)
    print("  1 2 3 4 5 6 7")
    for i = 1, 7 do
        io.write(i .. " ")
        for j = 1, 7 do
            io.write(board[i][j] .. " ")
        end
        io.write("\n")
    end
end

-- 检查是否有可消除的图案，并返回消除后的棋盘和分数
function check_matches(board)
    local score = 0
    for i = 1, 7 do
        for j = 1, 7 do
            local pattern = board[i][j]
            if pattern ~= " " then
                local count = 1
                for k = j + 1, 7 do
                    if board[i][k] == pattern then
                        count = count + 1
                    else
                        break
                    end
                end
                if count >= 3 then
                    for k = j, j + count - 1 do
                        board[i][k] = " "
                    end
                    score = score + 1
                end
                count = 1
                for k = i + 1, 7 do
                    if board[k][j] == pattern then
                        count = count + 1
                    else
                        break
                    end
                end
                if count >= 3 then
                    for k = i, i + count - 1 do
                        board[k][j] = " "
                    end
                    score = score + 1
                end
            end
        end
    end
    -- 下落图案
    for j = 1, 7 do
        local count = 0
        for i = 7, 1, -1 do
            if board[i][j] ~= " " then
                count = count + 1
                board[count][j] = board[i][j]
                if count < i then
                    board[i][j] = " "
                end
            end
        end
        for i = count + 1, 7 do
            board[i][j] = " "
        end
    end
    return board, score
end

-- 游戏主循环
local steps = 30
local score = 0
while steps > 0 do
    print_board(board)
    print("Score: " .. score .. "   Steps left: " .. steps)
    -- 获取操作
    io.write("Enter move (format: x1 y1 x2 y2): ")
    local input = io.read("*line")
    local x1, y1, x2, y2 = input:match("(%d+) (%d+) (%d+) (%d+)")
    x1, y1, x2, y2 = tonumber(x1), tonumber(y1), tonumber(x2), tonumber(y2)
    -- 交换图案
    local temp = board[x1][y1]
    board[x1][y1] = board[x2][y2]
    board[x2][y2] = temp
    -- 检查图案是否可消除
    board, delta_score = check_matches(board)
    score = score + delta_score
    steps = steps - 1
end

-- 游戏结束，输出最终分数
print("Game over! Final score: " .. score)

实现过程中，按照需求初始化棋盘并填充图案，然后进入主循环，每次循环先打印当前棋盘和分数，然后获取用户输入并执行操作，再检查是否有可消除的图案，消除后图案自由下落，最后减少步数并进入下一轮循环，直到步数用完为止。游戏结束后输出最终分数。

由于没有图形界面，无法显示动态效果，但可以在终端上看到每一步的变化和分数。