Scala 2.9.1．
object Main {
type Pair = (Int, Int)
// Comparing the second element of 2-tuple
object MyTupleOrdering extends Ordering[Pair] {
def compare(a: Pair, b: Pair) = - (a._2 compare b._2)
}
def main(args: Array[String]) = {
import scala.collection.mutable.PriorityQueue
val pq = PriorityQueue[Pair]()(MyTupleOrdering)
val _list = List[Pair]( (1, 2), (2, 1), (3, 5), (5, 7) )
for (v < - _list) pq += v
while (!pq.isEmpty) {
val top = pq.dequeue
println("->(%d,%d)".format(top._1, top._2))
}
}
}
出力
cocomoff[10:20午前]% scala Sample.scala ->(2,1) ->(1,2) ->(3,5) ->(5,7)
何をやろうとしてたんだっけ？
