title: back tracking algorithm design technique definition
body: <p>I am reading about backtracking algorithm design technique. It is mentioned as follows.</p>
  
  <blockquote>
    <p>Backtracking is a refinement of the brute force approach, which
    systematically searches for a solution to a problem among all
    available options. It does so by assuming that the solutions are
    represented by vectors <em>(v1, v2, ..., vm)</em> of values and by traversing,
    in a depth first manner, the domains of the vectors until the
    solutions are found.</p>
  </blockquote>
  
  <p>My quesitons on above text as follows.</p>
  
  <ol>
  <li><p>What does author mean by solutions are represented by vectors?</p></li>
  <li><p>What does author mean by domains of vectors?</p></li>
  </ol>
  
  <p>Thanks for clarifying.</p>