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    <p>You don't need to sort the entire collection in order to determine the top N elements. However, I don't believe that this functionality is supplied by the raw library, so you would have to roll you own, possibly using the <em>pimp-my-library</em> pattern.</p> <p>For example, you can get the nth element of a collection as follows:</p> <pre><code> class Pimp[A, Repr &lt;% TraversableLike[A, Repr]](self : Repr) { def nth(n : Int)(implicit ord : Ordering[A]) : A = { val trav : TraversableLike[A, Repr] = self var ltp : List[A] = Nil var etp : List[A] = Nil var mtp : List[A] = Nil trav.headOption match { case None =&gt; error("Cannot get " + n + " element of empty collection") case Some(piv) =&gt; trav.foreach { a =&gt; val cf = ord.compare(piv, a) if (cf == 0) etp ::= a else if (cf &gt; 0) ltp ::= a else mtp ::= a } if (n &lt; ltp.length) new Pimp[A, List[A]](ltp.reverse).nth(n)(ord) else if (n &lt; (ltp.length + etp.length)) piv else new Pimp[A, List[A]](mtp.reverse).nth(n - ltp.length - etp.length)(ord) } } } </code></pre> <p>(This is not very functional; sorry)</p> <p>It's then trivial to get the top <code>n</code> elements:</p> <pre><code>def topN(n : Int)(implicit ord : Ordering[A], bf : CanBuildFrom[Repr, A, Repr]) ={ val b = bf() val elem = new Pimp[A, Repr](self).nth(n)(ord) import util.control.Breaks._ breakable { var soFar = 0 self.foreach { tt =&gt; if (ord.compare(tt, elem) &lt; 0) { b += tt soFar += 1 } } assert (soFar &lt;= n) if (soFar &lt; n) { self.foreach { tt =&gt; if (ord.compare(tt, elem) == 0) { b += tt soFar += 1 } if (soFar == n) break } } } b.result() } </code></pre> <p>Unfortunately I'm having trouble getting this pimp to be discovered via this implicit:</p> <pre><code>implicit def t2n[A, Repr &lt;% TraversableLike[A, Repr]](t : Repr) : Pimp[A, Repr] = new Pimp[A, Repr](t) </code></pre> <p>I get this:</p> <pre><code>scala&gt; List(4, 3, 6, 7, 1, 2, 8, 5).topN(4) &lt;console&gt;:9: error: could not find implicit value for evidence parameter of type (List[Int]) =&gt; scala.collection.TraversableLike[A,List[Int]] List(4, 3, 6, 7, 1, 2, 8, 5).topN(4) ^ </code></pre> <p>However, the code actually works OK:</p> <pre><code>scala&gt; new Pimp(List(4, 3, 6, 7, 1, 2, 8, 5)).topN(4) res3: List[Int] = List(3, 1, 2, 4) </code></pre> <p>And</p> <pre><code>scala&gt; new Pimp("ioanusdhpisjdmpsdsvfgewqw").topN(6) res2: java.lang.String = adddfe </code></pre>
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