title: how to represent a number as a sum of 4 primes?
body: <p>Here is the problem (<a href="http://acm.uva.es/p/v101/10168.html" rel="nofollow">Summation of Four Primes</a>) states that :</p>
  
  <blockquote>
    <p>The input contains one integer number N (N&lt;=10000000) in every line. This is the number you will have to express as a summation of four primes</p>
    
    <p>Sample Input:<br> 24 <br> 36 <br> 46
    <br></p>
    
    <p>Sample Output: <br> 3 11 3 7 <br> 3
    7 13 13 <br> 11 11 17 7 <br></p>
  </blockquote>
  
  <p>This idea comes to my mind at a first glance </p>
  
  <ul>
  <li>Find all primes below N</li>
  <li>Find length of list (.length = 4) with Integer Partition problem (Knapsack)</li>
  </ul>
  
  <p>but complexity is very bad for this algorithm I think. This problem also looks like <a href="http://en.wikipedia.org/wiki/Goldbach%27s_conjecture" rel="nofollow">Goldbach's_conjecture</a>
  more. How can I solve this problem?</p>