title: Knapsack with "at least X value" constraint
body: <p>How would you go about solving this variation of Knapsack?</p>
  
  <p>You have n objects (x1,...xn), each with cost ci and value vi (1&lt;=i&lt;=n) and an additional constraint X, which is a lower bound on the value of the items selected.
  Find a subset of x1,...,xn that minimizes the cost of the items with a value of at least X.</p>
  
  <p>I am trying to solve this through Dynamic Programming, and what I thought of was to modify the usual table used into K[n,c,X] where X would be the minimum value I need to reach, but that seems to bring me nowhere. Any good ideas?</p>