title: Dynamic programming and Divide and conquer
body: <p>I was reading <a href="http://www.es.ele.tue.nl/education/5MC10/Solutions/knapsack.pdf" rel="noreferrer">notes on Dynamic programming</a>, and I encountered the following comment.</p>
  
  <blockquote>
    <p>If the subproblems are not independent, i.e.
    subproblems share subsubproblems, then a divideand-conquer algorithm repeatedly solves the common
    subsubproblems.
    Thus, it does more work than necessary</p>
  </blockquote>
  
  <p>What does this mean ? Can you give me examples to make the above point clear ?</p>