2008_q_a.scala

import scala.collection.mutable.Set

object SelfSearch {
  def arrayToSet(a : Array[String]) = {
    Set(a: _*)
  }

  def solveCase(engines: Array[String], queries: Array[String]): Int = {
    var enginesLeft = arrayToSet(engines)
    var switches = 0

    for (query: String <- queries) {
      enginesLeft -= query
      if (enginesLeft.isEmpty) {
        enginesLeft = arrayToSet(engines)
        enginesLeft -= query
        switches += 1
      }
    }
    switches
  }

  def main(args: Array[String]) {
    val testCount = readLine().toInt
    for (i <- 0 until testCount) {
      // test case parameters
      val engineCount = readLine().toInt
      val engines = new Array [String] (engineCount)

      for (j <- 0 until engineCount) {
        engines(j) = readLine()
      }

      val queryCount = readLine().toInt
      val queries = new Array [String] (queryCount)

      for (j <- 0 until queryCount) {
        queries(j) = readLine()
      }

      val switches = solveCase(engines, queries)
      println("Case #%d: %d".format(i + 1, switches))
    }
  }
}


// time cat large.in | scala-2.9 -classpath . SelfSearch > large.out
// real 0m0.534s
// user 0m0.673s
// sys  0m0.069s

p008.scm

(use extras)

(define read-lines
  (lambda ()
    (let ((line (read-line)))
      (cond
        ((eof-object? line) '())
        (else (cons line (read-lines)))))))

(define join
  (lambda (lines)
    (apply string-append lines)))

(define char-as-int
  (lambda (char)
    ;; ord(0) -> 48
    (- (char->integer char) 48)))

;; srfi-1 take is strict about list length
(define take
  (lambda (l k)
    (cond
      ((null? l) '())
      ((<= k 0) '())
      (else (cons (car l)
                  (take (cdr l) (- k 1)))))))

(define quintets
  (lambda (l)
    (cond
      ((null? l) '())
      (else (cons (take l 5)
                  (quintets (cdr l)))))))

(define product
  (lambda (l)
    (apply * l)))

(let* ((lines (join (read-lines)))
       (num-list (map char-as-int (string->list lines)))
       (products (map product (quintets num-list))))
  (print (apply max products)))

;real  0m0.013s
;user  0m0.007s
;sys   0m0.007s