title: Can someone help solve this recurrence relation?
body: <pre><code>T(n) = 2T(n/2) + 0(1)
  
  T(n) = T(sqrt(n)) + 0(1)
  </code></pre>
  
  <p>In the first one I use substitution method for n, logn, etc; all gave me wrong answers.<br>
  Recurrence trees: I don't know if I can apply as the root will be a constant.</p>
  
  <p>Can some one help?</p>