Catalan numbers: Difference between revisions

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@@ Line 1,891: / Line 1,891: @@
 =={{header|Kotlin}}==
-{{trans|Java}}
 {{works with|Java|1.7.0}}
 {{works with|Kotlin|1.0.0}}
@@ Line 1,897: / Line 1,896: @@
 <lang scala>import net.openhft.koloboke.collect.map.hash.HashIntDoubleMaps.*
-object Catalan {
+abstract class Catalan {
-    fun catI(n: Int): Double {
+    abstract operator fun invoke(n: Int) : Double
-        if (n !in catsI)
-            catsI[n] = Math.round(fact(2 * n) / (fact(n + 1) * fact(n))).toDouble()
+    protected val m = newUpdatableMapOf(0 , 1.0)
-        return catsI[n]
+}
-    }
+object CatalanI : Catalan() {
-    fun catR1(n: Int): Double {
-        if (n in catsR1)
+    override fun invoke(n: Int): Double {
-            return catsR1[n]
+        if (n !in m)
+            m[n] = Math.round(fact(2 * n) / (fact(n + 1) * fact(n))).toDouble()
-        var sum = 0.0
+        return m[n]
-        for (i in 0..n - 1)
-            sum += catR1(i) * catR1(n - 1 - i)
-        sum = Math.round(sum).toDouble()
-        catsR1[n] = sum
-        return sum
-    }
-    fun catR2(n: Int): Double {
-        if (n !in catsR2)
-            catsR2[n] = Math.round(2.0 * (2 * (n - 1) + 1) / (n + 1) * catR2(n - 1)).toDouble()
-        return catsR2[n]
     }
@@ Line 1,928: / Line 1,912: @@
         if (n in facts)
             return facts[n]
+        var f = n * fact(n -1)
-        var f = 2.0
-        for (i in 3..n)
-            f *= i
         facts[n] = f
         return f
@@ Line 1,938: / Line 1,918: @@
     private val facts = newUpdatableMapOf(0 , 1.0, 1 , 1.0, 2 , 2.0)
+}
-    private val catsI = newUpdatableMapOf(0 , 1.0)
-    private val catsR1 = newUpdatableMapOf(0 , 1.0)
+object CatalanR1 : Catalan() {
-    private val catsR2 = newUpdatableMapOf(0 , 1.0)
+    override fun invoke(n: Int): Double {
+        if (n in m)
+            return m[n]
+        var sum = 0.0
+        for (i in 0..n - 1)
+            sum += invoke(i) * invoke(n - 1 - i)
+        sum = Math.round(sum).toDouble()
+        m[n] = sum
+        return sum
+    }
+}
+object CatalanR2 : Catalan() {
+    override fun invoke(n: Int): Double {
+        if (n !in m)
+            m[n] = Math.round(2.0 * (2 * (n - 1) + 1) / (n + 1) * invoke(n - 1)).toDouble()
+        return m[n]
+    }
 }
 fun main(args: Array<String>) {
+    val c = arrayOf(CatalanI, CatalanR1, CatalanR2)
-    for(i in 0..15)
+    for(i in 0..15) {
-        println( "[%9d %9d %9d]".format(Catalan.catI(i).toLong(), Catalan.catR1(i).toLong(), Catalan.catR2(i).toLong()))
+        c.forEach { print("%9d".format(it(i).toLong())) }
+        println()
+    }
 }</lang>
 {{out}}
-<pre>[        1         1         1]
+<pre>        1        1        1
-[        1         1         1]
+1        1
-[        2         2         2]
+2        2
-[        5         5         5]
+5        5
-[       14        14        14]
+14       14
-[       42        42        42]
+42       42
-[      132       132       132]
+132      132
-[      429       429       429]
+429      429
-[     1430      1430      1430]
+1430     1430
-[     4862      4862      4862]
+4862     4862
-[    16796     16796     16796]
+16796    16796
-[    58786     58786     58786]
+58786    58786
-[   208012    208012    208012]
+208012   208012
-[   742900    742900    742900]
+742900   742900
-[  2674440   2674440   2674440]
+  2674440  2674440  2674440
-[  9694845   9694845   9694845]</pre>
+  9694845  9694845  9694845</pre>
 =={{header|Liberty BASIC}}==