Data commit

Task/Van-Eck-sequence/Kotlin/van-eck-sequence.kotlin

@@ -0,0 +1,23 @@
+fun main() {
+    println("First 10 terms of Van Eck's sequence:")
+    vanEck(1, 10)
+    println("")
+    println("Terms 991 to 1000 of Van Eck's sequence:")
+    vanEck(991, 1000)
+}
+
+private fun vanEck(firstIndex: Int, lastIndex: Int) {
+    val vanEckMap = mutableMapOf<Int, Int>()
+    var last = 0
+    if (firstIndex == 1) {
+        println("VanEck[1] = 0")
+    }
+    for (n in 2..lastIndex) {
+        val vanEck = if (vanEckMap.containsKey(last)) n - vanEckMap[last]!! else 0
+        vanEckMap[last] = n
+        last = vanEck
+        if (n >= firstIndex) {
+            println("VanEck[$n] = $vanEck")
+        }
+    }
+}