title: Find if entire range is covered up given a set of N intervals
body: <p>Suppose I have N intervals of the form [start,end]. I need to find out if an entire range is covered up by these intervals .</p>
  
  <p>For eg: If my intervals are [4.5,5.765] and [5.8,10] and the interval is [5,10] it should report false where as for the same data if interval is [6,9.99] it should report true.</p>
  
  <p>I need a precision of 1e-9.And intervals as well as range will be in [-1000,1000].</p>
  
  <p>Is this problem solvable in O(NlgN) time ?? Where N=number of intervals .</p>