title: Fibonacci numbers algorithm
body: <p>The most common recursive algorithm for Fibonacci sequences looks something like this:</p>
  
  <pre><code>unsigned int fib(unsigned int n){
     return (n &lt; 2) ? n : fib(n - 1) + fib(n - 2);
  }
  </code></pre>
  
  <p>What is the most efficient fibonacci algorithm in terms of time and space complexity?</p>