title: Compare two string as numeric value
body: <p>How should I compare two string representing numbers in C++? I thought of converting to number of <code>long long</code> type but the problem is the numerical value represented by string can exceed the <code>long long</code> MAX limit. 
  It is guaranteed that the string represents a numerical value.</p>
  
  <p>There is a similar question in Java <a href="https://stackoverflow.com/questions/15764228/compare-two-numeric-string-values">compare two numeric String values</a>.
  but that makes use of the BigInteger Library that we don't have in C++.</p>