5月13日，北京市第八十中学学生展示自己设计制作的仿生学设备。 新京报记者 王飞 摄
Intel documentation describes the 386's Protection Test Unit as a component that "implements fast testing of complex memory protection functions." It is mostly composed of a PLA (Programmable Logic Array), referred to as Test PLA by Intel, that is physically visible by its regular appearance on the die. This single piece of combinational logic replaces what would otherwise be dozens of multi-cycle conditional branches in the microcode. Instead of testing privilege rules sequentially, the microcode issues a single protection test operation, and the PLA evaluates all applicable rules in parallel, producing a complete decision in one evaluation: continue, fault, or redirect to a gate handler.
，详情可参考搜狗输入法2026
* @param arr 待排序数组。爱思助手下载最新版本是该领域的重要参考
* 获取数字的第digit位（从右往左，0表示个位）。Line官方版本下载对此有专业解读