title: Time-complexity of recursive algorithm for calculating binomial coefficient
body: <p>I'm studying about algorithm complexity analysis. I have problem with unconformity or <code>C(n, k)</code>.</p>
  
  <pre><code>int C(int n, int k){
     if(n==k || k==0)
       return 1;
     return C(n-1, k) + C(n-1, k-1);
  }
  </code></pre>
  
  <p>How can I determine its execution complexity or <code>T(n)</code>?</p>