Knapsack using dynamic programming.

Knapsack.scala

object Knapsack {
  val W = 10000 // capacity
  val n = 100   // number of items 
  val file = "path-to-your-file-contains-<size> <weight> lines"
  val c = Array.ofDim[Int](n, W)
  val lines = Source.fromFile(file).getLines.drop(1).toList.map(_.split(" ").map(_.toInt))
  def main(args: Array[String]) {
    0 until W foreach { x =>  c(0)(x) = 0 }
    for (i <- 1 until n; x <- 0 until W) c(i)(x) = math.max(c(i - 1)(x), { if (lines(i)(1) > x) 0 else c(i - 1)(x - lines(i)(1)) + lines(i)(0) })
    print(c(n-1)(W-1))
  }
  
  /* 
  your text file should contain the lines 
  [knapsack_size][number_of_items]
  [value_1] [weight_1]
  [value_2] [weight_2]
  */