网络连接信息

  1. 什么是子网掩码?
    1. 它是一种用来指明一个IP地址的哪些位标识的是主机所在的子网,以及哪些位标识的是主机的位的掩码。
  2. 什么是默认网关
    1. 局域网里面统一收发信息的机器的IP
  3. 什么是DHCP服务器?
    1. 用来为局域网中的电脑默认分发IP的机器,遵守DHCP(一种协议);
  4. 什么是NAT?
    1. 连接内网与外网的中转站;
  5. 什么是DNS?
    1. 一个将域名与IP相互映射的数据库

FM-index

In computer science, an FM-index is a compressed full-text substring index based on the Burrows-Wheeler transform, with some similarities to the suffix array. It was created by Paolo Ferragina and Giovanni Manzini, who describe it as an opportunistic data structure as it allows compression of the input text while still permitting fast substring queries. The name stands for Full-text index in Minute space.

It can be used to efficiently find the number of occurrences of a pattern within the compressed text, as well as locate the position of each occurrence. Both the query time and storage space requirements are sublinear[clarification needed] with respect to the size of the input data.

The original authors have devised improvements to their original approach and dubbed it “FM-Index version 2“. A further improvement, the alphabet-friendly FM-index, combines the use of compression boosting and wavelet trees to significantly reduce the space usage for large alphabets.

The FM-index has found use in, among other places, bioinformatics.