reddit 214H solution

crappy.scala

import scala.io.Source
import scala.math._

def dist(x:(Double, Double), y:(Double, Double)): Double = 
    sqrt(pow(x._1-y._1, 2.0) + pow(x._2-y._2, 2.0))

// yields a 3-tuple: distance to travel, closest treat pos, remaining treats
def best(pos:(Double, Double), treats:List[(Double,Double)]): (Double, (Double, Double), List[(Double,Double)])= {
    val sorted = treats.map(x => (dist(pos, x),x)).sortBy(_._1)
    (sorted.head._1, sorted.head._2, sorted.tail.map(_._2))
}

def read(): List[(Double,Double)] = 
    Source.fromFile("/tmp/input.txt").getLines.toList.tail.map(_.split(" ").map(_.toDouble)).map(x=>(x(0), x(1))).toList

def main(): Double = {
    def loop(pos:(Double,Double), treats:List[(Double, Double)], dist: Double): Double = {
        treats match {
            case Nil => dist
            case _   => val (l, newtreat, remaining) = best(pos, treats)
                        loop(newtreat, remaining, dist+l)
        }
    }
    loop((0.5, 0.5), read(), 0.0)
}