Card shuffles: Difference between revisions
Added Kotlin
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(Added Kotlin) |
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Line 326:
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20]
[18, 12, 13, 14, 2, 3, 15, 5, 9, 19, 7, 11, 1, 6, 4, 20, 16, 17, 10, 8]</pre>
=={{header|Kotlin}}==
<lang scala>// version 1.1.51
import java.util.Random
import java.util.Collections.shuffle
val r = Random()
fun riffle(deck: List<Int>, iterations: Int): List<Int> {
val pile = deck.toMutableList()
repeat(iterations) {
val mid = deck.size / 2
val tenpc = mid / 10
// choose a random number within 10% of midpoint
val cut = mid - tenpc + r.nextInt(2 * tenpc + 1)
// split deck into two at cut point
val deck1 = pile.take(cut).toMutableList()
val deck2 = pile.drop(cut).toMutableList()
pile.clear()
val fromTop = r.nextBoolean() // choose to draw from top or bottom
while (deck1.size > 0 && deck2.size > 0) {
if (fromTop) {
pile.add(deck1.removeAt(0))
pile.add(deck2.removeAt(0))
}
else {
pile.add(deck1.removeAt(deck1.lastIndex))
pile.add(deck2.removeAt(deck2.lastIndex))
}
}
// add any remaining cards to the pile and reverse it
if (deck1.size > 0) pile.addAll(deck1)
else if (deck2.size > 0) pile.addAll(deck2)
pile.reverse() // as pile is upside down
}
return pile
}
fun overhand(deck: List<Int>, iterations: Int): List<Int> {
val pile = deck.toMutableList()
val pile2 = mutableListOf<Int>()
val twentypc = deck.size / 5
repeat(iterations) {
while (pile.size > 0) {
val cards = minOf(pile.size, 1 + r.nextInt(twentypc))
pile2.addAll(0, pile.take(cards))
repeat(cards) { pile.removeAt(0) }
}
pile.addAll(pile2)
pile2.clear()
}
return pile
}
fun main(args: Array<String>) {
println("Starting deck:")
var deck = List<Int>(20) { it + 1 }
println(deck)
val iterations = 10
println("\nRiffle shuffle with $iterations iterations:")
println(riffle(deck, iterations))
println("\nOverhand shuffle with $iterations iterations:")
println(overhand(deck, iterations))
println("\nStandard library shuffle with 1 iteration:")
shuffle(deck) // shuffles deck in place
println(deck)
}</lang>
Sample output:
<pre>
Starting deck:
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20]
Riffle shuffle with 10 iterations:
[5, 18, 3, 12, 15, 6, 8, 16, 2, 20, 17, 11, 13, 1, 9, 14, 19, 7, 10, 4]
Overhand shuffle with 10 iterations:
[2, 8, 1, 4, 11, 7, 3, 5, 17, 12, 10, 9, 6, 18, 20, 14, 19, 13, 15, 16]
Standard library shuffle with 1 iteration:
[17, 9, 12, 15, 7, 13, 18, 8, 2, 20, 5, 10, 16, 6, 14, 4, 19, 3, 11, 1]
</pre>
=={{header|Lua}}==
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