[scala]無限リストを用いたモンテカルロ法比較

monte.scala

package scalatan
 
import util.Random
import math._
 
object Main {
 	def main(args: Array[String]): Unit = {
		def create() : Stream[Double] = {
			Stream.cons(Random.nextDouble(),create())
		}
		val n = 1000
		val hit = create() zip create() take n filter(x => x._1 * x._1 + x._2 * x._2 <= 1.0 )
		print(4.0 * hit.length / n)
	}
}

monte_old.scala

package scalatan
 
import util.Random
import math._
 
object Main {
 
	def main(args: Array[String]): Unit = {
		val n = 1000
		var hit = 0
		for(i <- 0 until n){
			val x = Random.nextDouble()
			val y = Random.nextDouble()
			if(x * x + y * y <= 1.0) hit +=1
		}
		print(4.0 * hit / n)
	}
}