矩形切割

思想：跟家里铺瓷砖的想法是一样的

给出大矩形的宽高：width, height

切块的宽高：span(width, height)

def slice_rectangle(width, height, span):
    shape = [0, 0]  # 高宽
    blocks = []
    # (lx,ly) 左上角。（bx,by）右下角
    lx = 0
    ly = 0
    bx = 0
    by = 0
    while by < height:
        by = ly + span
        if by > height:
            by = height
        lx = bx = 0
        shape[0] = shape[0] +1
        shape[1] = 0
        while bx < 
            shape[1] = shape[1] + 1
            bx = lx + span
            if bx > 
                bx = width
            block = [lx, ly, bx, by]  # 对应位置: 坐上x,y 和 右下x.y的坐标
            blocks.append(block)
            lx = bx
        ly = by
    # 返回切割的形状和每个切割块的坐标
    return shape,blocks