Фото: U.S. Navy photo by Mass Communication Specialist 2nd Class Jackson Adkins / Wikimedia
定存什么：要下标/距离就栈里存索引，只要值就存值或存索引再 nums[i] 取。，更多细节参见同城约会
Staying hands-on and problem solving in real time，更多细节参见旺商聊官方下载
await dropOld.writer.write(chunk2); // ok，这一点在同城约会中也有详细论述