import collection.immutable._
import collection.parallel._//immutable._
class SeqCoder(words: List[String]) {
private val m = Map(
'2' -> "ABC", '3' -> "DEF", '4' -> "GHI", '5' -> "JKL",
'6' -> "MNO", '7' -> "PQRS", '8' -> "TUV", '9' -> "WXYZ")
/** Invert the mnemonics map to give a map from chars 'A' ... 'Z' to '2' ... '9' */
private val charCode: Map[Char, Char] =
for ((digit, letters) <- m; letter <- letters) yield letter -> digit
/** Maps a word to the digit string it represents,
* e.g. `Java` -> `5282` */
private def wordCode(word: String): String = word.toUpperCase map charCode
/** A map from digit strings to the words that represent
* them e.g. `5282` -> List(`Java`, `Kata`, `Lava`, ...)
*/
val wordsForNum: Map[String, Seq[String]] =
(words groupBy wordCode).map(t => (t._1, t._2.toSeq)) withDefaultValue Seq()
val memo = collection.mutable.Map[String, Set[Seq[String]]]("" -> Set(Seq()))
val wfnmemo = collection.mutable.Map[(String, String), Set[Seq[String]]]()
val subsmemo = collection.mutable.Map[(String, String, String), Set[Seq[String]]]()
/** All ways to encode a number as a list of words */
def encode(number: String): Set[Seq[String]] =
if (number.isEmpty) Set(Seq())
else {
val splits = (1 to number.length).toSet
// for {
// split <- splits
// word <- wordsForNum(number take split)
// rest <- encode(number drop split)
// } yield word :: rest
val r = splits.flatMap(split => {
val wfn = wordsForNum(number take split).flatMap(word => {
val subs = encode(number drop split)
val subsmapped = subs.map(rest => word +: rest)
subsmemo += (number, number drop split, word) -> subsmapped
subsmapped
})
wfnmemo += (number, number take split) -> wfn.toSet
wfn
})
memo += number -> r
r
}
/** Maps a number to a list of all word phrases that can
* represent it */
def translate(number: String): Set[String] = encode(number) map (_ mkString " ")
def ??? : Nothing = throw new UnsupportedOperationException
}
class ParCoder(words: List[String]) {
private val m = Map(
'2' -> "ABC", '3' -> "DEF", '4' -> "GHI", '5' -> "JKL",
'6' -> "MNO", '7' -> "PQRS", '8' -> "TUV", '9' -> "WXYZ")
/** Invert the mnemnonics map to give a map from chars 'A' ... 'Z' to '2' ... '9' */
private val charCode: Map[Char, Char] =
for ((digit, letters) <- m; letter <- letters) yield letter -> digit
/** Maps a word to the digit string it represents,
* e.g. `Java` -> `5282` */
private def wordCode(word: String): String = word.toUpperCase map charCode
/** A map from digit strings to the words that represent
* them e.g. `5282` -> List(`Java`, `Kata`, `Lava`, ...)
*/
val wordsForNum: Map[String, ParSeq[String]] =
(words groupBy wordCode).map(t => (t._1, t._2.toSeq.par)) withDefaultValue ParSeq()
val comparison = new SeqCoder(words)
/** All ways to encode a number as a list of words */
def encode(number: String): ParSet[ParSeq[String]] =
if (number.isEmpty) ParSet(ParSeq())
else {
val splits = (1 to number.length).toSet.par
// for {
// split <- splits
// word <- wordsForNum(number take split)
// rest <- encode(number drop split)
// } yield word :: rest
val r = splits.flatMap(split => {
val wfn = wordsForNum(number take split).flatMap(word => {
val subs = encode(number drop split)
assertNumber(number drop split, subs)
val subsmapped = subs.map(rest => word +: rest)
assertSubs(number, number drop split, word, subsmapped)
subsmapped
})
assertWfn(number, number take split, number drop split, wfn)
wfn
})
assertNumber(number, r)
r
}
def assertSubs(num: String, subsfrom: String, word: String, r: ParSet[ParSeq[String]]) {
val m = comparison.subsmemo((num, subsfrom, word))
if (r != m) {
println("map for number from subs and word: " + num + ", " + subsfrom + ", " + word)
println("parset: " + r.size)
println("memoed: " + m.size)
error("r != m")
}
}
def assertWfn(num: String, split: String, dropped: String, r: ParSeq[ParSeq[String]]) {
val m = comparison.wfnmemo((num, split))
val rs = r.toSet.par
val words: ParSeq[String] = wordsForNum(split)
if (rs != m) {
println("flatmap for number with split: " + num + ", " + split)
println("words for: " + words)
println("parset: " + rs.size)
println("memoed: " + m.size)
println("retrying...")
for (i <- 0 until 30) {
val r2: ParSeq[ParSeq[String]] = words.flatMap(word => {
val subs: ParSet[ParSeq[String]] = encode(dropped)
println("subs size for '" + dropped + "': " + subs.size)
val subsmapped: ParSet[ParSeq[String]] = subs.map(rest => word +: rest)
println("map size: " + subsmapped.size)
subsmapped.toList
})
println(i + ") retry size: " + r2.size)
}
error("rs != m")
}
}
def assertNumber(num: String, r: ParSet[ParSeq[String]]) {
val m = comparison.memo(num)
if (r != m) {
println("for number: " + num)
println("parset: " + r.size)
println("memoed: " + m.size)
error("r != m")
}
}
/** Maps a number to a list of all word phrases that can
* represent it */
def translate(number: String): ParSet[String] = {
comparison.translate(number)
encode(number) map (_.seq mkString " ")
}
def ??? : Nothing = throw new UnsupportedOperationException
}
/** Test code */
object Test {
val code = "2328437472947"//36262633"//837976"//"6477323986225453446"
//val code = "747294736262633"
/* */
def main(args : Array[String]) {
for (i <- 0 until 10) {
val seqcoder = new SeqCoder(Dictionary.wordlist)
val sts = seqcoder.translate(code)
//println("Translation check: " + st.size)
val parcoder = new ParCoder(Dictionary.wordlist)
val pts = parcoder.translate(code)
//println("Translation check: " + pt.size)
val st = sts.toList.sorted
val pt = pts.toList.sorted
if (st.size != pt.size) {
val zipped = st.zip(pt)
val ind = zipped.indexWhere { case (a, b) => a != b }
val sliced = zipped.slice(ind - 10, ind + 10)
//println(sliced.map(t => t._1 + "\n" + t._2 + "\n--------").mkString("\n"))
//println(i + ") seq vs par: " + st.size + " vs " + pt.size)
}
if (st != pt) {
val zipped = (st.toList.sorted zip pt.toList.sorted);
val diffp = zipped indexWhere { case (x, y) => x != y }
//println(zipped/*.slice(diffp - 10, diffp + 10)*/ mkString ("\n"))
//println((st.toList.sorted zip pt.toList.sorted) map { case (x, y) => (x == y) } reduceLeft(_ && _))
}
assert(st == pt)
}
}
}
