用qbasic编写俄罗斯方块

以下是一个简单的用 QBASIC 编写的俄罗斯方块游戏：

SCREEN 12 ' 设置屏幕模式为 640x480 16 色

' 定义方块的形状和颜色
DIM block(7, 3, 3) AS INTEGER
block(0, 0, 0) = 0: block(0, 0, 1) = 0: block(0, 0, 2) = 0: block(0, 0, 3) = 0
block(0, 1, 0) = 0: block(0, 1, 1) = 0: block(0, 1, 2) = 0: block(0, 1, 3) = 0
block(0, 2, 0) = 1: block(0, 2, 1) = 1: block(0, 2, 2) = 1: block(0, 2, 3) = 1
block(0, 3, 0) = 0: block(0, 3, 1) = 0: block(0, 3, 2) = 0: block(0, 3, 3) = 0
' ... 其他方块的定义

DIM color(7) AS INTEGER
color(0) = 0: color(1) = 2: color(2) = 3: color(3) = 4: color(4) = 5: color(5) = 6: color(6) = 7: color(7) = 8

' 定义游戏区域
DIM board(10, 20) AS INTEGER

' 初始化游戏区域
FOR x = 0 TO 10
    FOR y = 0 TO 20
        board(x, y) = -1 ' -1 表示该位置没有方块
    NEXT y
NEXT x

' 显示游戏区域
FOR x = 0 TO 10
    FOR y = 0 TO 20
        IF board(x, y) >= 0 THEN ' 如果该位置有方块
            COLOR color(board(x, y)) ' 设置颜色
            LINE (x * 20, y * 20)-(x * 20 + 19, y * 20 + 19), , BF ' 绘制方块
        END IF
    NEXT y
NEXT x

' 定义当前方块和下一个方块
current_block = INT(RND * 7)
next_block = INT(RND * 7)

' 定义当前方块的位置和状态
current_x = 4
current_y = 0
current_rotation = 0

' 游戏循环
DO
    ' 显示游戏界面
    COLOR 15 ' 设置颜色为白色
    LINE (0, 0)-(199, 479), , B ' 绘制游戏区域边框
    FOR x = 0 TO 10
        FOR y = 0 TO 20
            IF board(x, y) >= 0 THEN ' 如果该位置有方块
                COLOR color(board(x, y)) ' 设置颜色
                LINE (x * 20, y * 20)-(x * 20 + 19, y * 20 + 19), , BF ' 绘制方块
            END IF
        NEXT y
    NEXT x
    FOR x = 0 TO 3
        FOR y = 0 TO 3
            IF block(current_block, current_rotation, y * 4 + x) > 0 THEN ' 如果该位置有方块
                COLOR color(current_block) ' 设置颜色
                LINE ((current_x + x) * 20, (current_y + y) * 20)-((current_x + x) * 20 + 19, (current_y + y) * 20 + 19), , BF ' 绘制方块
            END IF
        NEXT y
    NEXT x

    ' 检测用户输入
    DO WHILE INKEY$ <> ""
    LOOP
    k$ = INKEY$ ' 获取用户输入
    SELECT CASE k$
        CASE "a" ' 向左移动
            IF current_x > 0 THEN current_x = current_x - 1
        CASE "d" ' 向右移动
            IF current_x < 7 THEN current_x = current_x + 1
        CASE "w" ' 旋转
            IF current_rotation < 3 THEN current_rotation = current_rotation + 1 ELSE current_rotation = 0
        CASE "s" ' 加速下落
            current_y = current_y + 1
    END SELECT

    ' 计算下一个方块是否可以出现
    flag = 1
    FOR x = 0 TO 3
        FOR y = 0 TO 3
            IF block(next_block, 0, y * 4 + x) > 0 THEN ' 如果该位置有方块
                IF board(x + 4, y) >= 0 THEN flag = 0 ' 如果该位置已经有方块，则不允许出现
            END IF
        NEXT y
    NEXT x
    IF flag THEN ' 如果下一个方块可以出现
        current_block = next_block ' 设置当前方块
        current_x = 4 ' 设置当前方块位置
        current_y = 0
        current_rotation = 0 ' 设置当前方块状态
        next_block = INT(RND * 7) ' 生成下一个方块
    ELSE ' 如果下一个方块不能出现
        FOR y = 0 TO 3
            FOR x = 0 TO 3
                IF block(current_block, current_rotation, y * 4 + x) > 0 THEN ' 如果该位置有方块
                    board(current_x + x, current_y + y) = current_block ' 将该位置的方块加入游戏区域
                END IF
            NEXT x
        NEXT y
        ' 检测是否有一行已经被填满
        FOR y = 0 TO 19
            flag = 1
            FOR x = 0 TO 9
                IF board(x, y) < 0 THEN flag = 0 ' 如果该行有空位，则不符合条件
            NEXT x
            IF flag THEN ' 如果该行已经被填满
                FOR yy = y TO 1 STEP -1 ' 将上面的方块下移一行
                    FOR x = 0 TO 9
                        board(x, yy) = board(x, yy - 1)
                    NEXT x
                NEXT yy
            END IF
        NEXT y
    END IF

    ' 将当前方块下移一行
    flag = 1
    FOR y = 0 TO 3
        FOR x = 0 TO 3
            IF block(current_block, current_rotation, y * 4 + x) > 0 THEN ' 如果该位置有方块
                IF current_y + y + 1 > 19 THEN flag = 0 ' 如果已经到达底部，则不允许下移
                IF board(current_x + x, current_y + y + 1) >= 0 THEN flag = 0 ' 如果下一行已经有方块，则不允许下移
            END IF
        NEXT x
    NEXT y
    IF flag THEN current_y = current_y + 1

    SLEEP 50 ' 等待 50 毫秒
LOOP

请注意，这只是一个简单的实现，可能存在一些问题，并且还可以进行优化。