title: Find a combination of k numbers in a given sequence of numbers satisfying the condition
body: <p>I have a problem like this:</p>
  <blockquote>
  <p>Given a list of numbers with n <code>(10 &lt;= n &lt;= 60)</code> numbers <code>x1, x2,..., xn</code>
  such that <code>1 &lt;= xj &lt;= 10</code>. Enter the number k <code>(1 &lt;= k &lt;= 8)</code>, enter the
  number m <code>(0 &lt;= m &lt;= 9)</code>. Find a combination of k numbers in the given
  list of numbers such that the sum of the k numbers found modulo 10
  equals m. For example: for the sequence <code>N = {1,3,5,6,3,7,2,9,10,3,4,6}</code>
  with k = 3 and m = 5, then one of the satisfying combinations is <code>{5,6.4} -&gt; (5 + 6 + 4) % 10 = 5</code>.</p>
  </blockquote>
  <p>I want to find the optimal solution to the problem but i haven't found a way other than using recursion to brute-force. Is there a better way than brute-force?
  Thank you for your reading!</p>