title: How to store a number with certain precision?
body: <p>What I want to do is to calculate square root of a number <strong>N</strong> and than we have to store this square root with <strong>P</strong> correct decimal values.For example</p>
  
  <pre><code>  Lets,N=2 and P=100
  
    //I want to store square root till P correct decimal values 
    like storing 
    1.41421356237309504880...till 100 values
  </code></pre>
  
  <p><strong>EDIT -</strong> Initially I asked question for specifically c++ but as told by <strong>vsoftco</strong> that it is almost impossible for c++ to do this without boost.So I have tagged python too and not removed c++ tag in hope for correct answer in C++ </p>