hwiorn

def gmax(s: String) = { 
  def r1(cond: Boolean, k: Array[List[Int]], x: Int, y: Int,xop: (Int)=>Int, yop: (Int)=>Int): Int = { 
    if(cond) k(y)(x) * k(yop(y))(xop(x)) * k(yop(yop(y)))(xop(xop(x))) * k(yop(yop(yop(y))))(xop(xop(xop(x))))
    else 1
  }
  val k = s.split('\n').map{_.split(' ').map {_.toInt}.toList}
  val w = k(1).length
  List(for(y <- 0 to w-1; x <- 0 to w-1)
       yield(List(
     r1(x <= w-4, k, x, y, {_+1}, {n=>n}),

hwiorn

for(b<-(2 to 999); a<-(b to 999); if(a + b  < 1000 &&
	     	   	    	math.pow(a, 2) + math.pow(b, 2) == math.pow(1000-a-b, 2)))
	  println(a * b * (1000-a-b))

hwiorn

println((2L to 2000000L).filter(BigInt(_).isProbablePrime(1000)).sum)

hwiorn

println((
"73167176531330624919225119674426574742355349194934" +
"96983520312774506326239578318016984801869478851843" +
"85861560789112949495459501737958331952853208805511" +
"12540698747158523863050715693290963295227443043557" +
"66896648950445244523161731856403098711121722383113" +
"62229893423380308135336276614282806444486645238749" +
"30358907296290491560440772390713810515859307960866" +
"70172427121883998797908792274921901699720888093776" +
"65727333001053367881220235421809751254540594752243" +

hwiorn

println(Stream.from(2).filter{BigInt(_).isProbablePrime(8)}(10001-1))

hwiorn

println((math.pow((1 to 100).sum, 2) - (1 to 100).map(x=>x*x).sum).toInt)

hwiorn

//소수(<20)의 최대 제곱수(<20)를 모두 곱셈
println((2 to 20).filter(BigInt(_).isProbablePrime(5)).
           map(k => (1 to 4).map(math.pow(k, _)).
                 filter(_ <= 20).max).product.toInt)

hwiorn

println ((for(a <- (999 to 100 by -1); b <- (999 to 100 by -1); if((a * b).toString.reverse == (a * b).toString)) yield (a*b)).sorted.last)

hwiorn

def k(a: Long, s: Long = 2): Long = {
  if(a < 2) s
  else if(a % s == 0) k(a / s, s)
  else k(a, s+1)
}
println(k(600851475143L))

hwiorn

def fib(a: Int, b: Int, sum: Int, _until: Int): Int = {
  return if(a < _until) fib(b, a+b, If(a%2==0) sum+a else sum, _until) else sum
}
println(fib(1, 1, 0, 4000000))