1.Erlang二分搜索

从一个已排好序的列表中寻找是否包含某元素，返回true/false

2.为文本建立索引

给定一个由英文单词构成的文件，为文件中所有单词建立索引，记录每个单词出现的行号和每行出现的次数，并将索引存入一个文件。

-1.Erlang binary search from an already sorted list to find if a certain element, returns true/false 2. Establish a file index given by the English word composed of text, document indexing all words, each record line number and the number of words per line appears appears, and the index into a file.