擅长:python、mysql、java
<p>您正在处理内存中的两个文件(输入和输出)。如果文件太大(分页),可能会导致时间问题。Try(伪代码)</p>
<pre><code>Open input file for read
Open output file for write
Initialize counter to 1
While not EOF in input file
Read input line
If counter is odd
Write line to output file
Else
Write 20 first characters of line to output file
Increment counter
Close files
</code></pre>