How To Mark a String in a File?
<p>I have a text file. It is designed as following:</p>

<pre>
#1{1,12,345,867}
#2{123, 3243534, 2132131231} 
#3{234, 35345}
#4{}
</pre>

<p>...
(at the end of an each entry stands "\n")</p>

<p>That is an example. In fact my strings #number{number,number,...,number} could be really long...</p>

<p>Here is a template of a constructor of a class which works with this file: </p>

<pre><code>public Submatrix(String matrixFilePath, int startPos, int endPos) throws FileNotFoundException{

}
</code></pre>

<p>As you can see submatrix is determined by startPos and endPos numbers of strings of a matrix.</p>

<p>My question is : "How could I count strings to reach the right one?"
My file can contain billions of strings. Should I use LineNumberReader->readLine() billions times?????</p>
