Data update

Task/Yellowstone-sequence/EasyLang/yellowstone-sequence.easy

@@ -0,0 +1,38 @@
+func gcd a b .
+   if b = 0
+      return a
+   .
+   return gcd b (a mod b)
+.
+proc remove_at i . a[] .
+   for j = i + 1 to len a[]
+      a[j - 1] = a[j]
+   .
+   len a[] -1
+.
+proc yellowstone count . yellow[] .
+   yellow[] = [ 1 2 3 ]
+   num = 4
+   while len yellow[] < count
+      for i to len notyellow[]
+         test = notyellow[i]
+         if gcd yellow[-2] test > 1 and gcd yellow[-1] test = 1
+            break 1
+         .
+      .
+      if i <= len notyellow[]
+         yellow[] &= notyellow[i]
+         remove_at i notyellow[]
+      else
+         while gcd yellow[-2] num <= 1 or gcd yellow[-1] num <> 1
+            notyellow[] &= num
+            num += 1
+         .
+         yellow[] &= num
+         num += 1
+      .
+   .
+.
+print "First 30 values in the yellowstone sequence:"
+yellowstone 30 yellow[]
+print yellow[]

Task/Yellowstone-sequence/PARI-GP/yellowstone-sequence.parigp

@@ -0,0 +1,29 @@
+yellowstone(n) = {
+    my(a=3, o=2, u=[]);
+    if(n<3, return(n)); \\ Base case: return n if it is less than 3
+    print1("1, 2");  \\ Print initial values
+
+    for(i = 4, n,  \\ Iterate from 4 to n
+        print1(", "a);  \\ Print current value of a
+        u = setunion(u, Set(a));  \\ Add a to the set u
+
+        \\ Remove consecutive elements from u
+        while(#u > 1 && u[2] == u[1] + 1,
+            u = vecextract(u, "^1")
+        );
+
+        \\ Find next value of a
+        for(k = u[1] + 1, 1e10,
+            if(gcd(k, o) <= 1, next);  \\ Skip if gcd(k, o) is greater than 1
+            if(setsearch(u, k), next);  \\ Skip if k is in set u
+            if(gcd(k, a) != 1, next);  \\ Skip if gcd(k, a) is not 1
+            o = a;  \\ Update o to current a
+            a = k;  \\ Update a to k
+            break
+        )
+    );
+
+    a  \\ Return the final value of a
+}
+
+yellowstone(20);  \\ Call the function with n = 20

Task/Yellowstone-sequence/Scala/yellowstone-sequence.scala

@@ -0,0 +1,42 @@
+import scala.util.control.Breaks._
+
+
+object YellowstoneSequence extends App {
+
+  println(s"First 30 values in the yellowstone sequence:\n${yellowstoneSequence(30)}")
+
+  def yellowstoneSequence(sequenceCount: Int): List[Int] = {
+    var yellowstoneList = List(1, 2, 3)
+    var num = 4
+    var notYellowstoneList = List[Int]()
+
+    while (yellowstoneList.size < sequenceCount) {
+      val foundIndex = notYellowstoneList.indexWhere(test =>
+        gcd(yellowstoneList(yellowstoneList.size - 2), test) > 1 &&
+        gcd(yellowstoneList.last, test) == 1
+      )
+
+      if (foundIndex >= 0) {
+        yellowstoneList = yellowstoneList :+ notYellowstoneList(foundIndex)
+        notYellowstoneList = notYellowstoneList.patch(foundIndex, Nil, 1)
+      } else {
+        breakable({
+        while (true) {
+          if (gcd(yellowstoneList(yellowstoneList.size - 2), num) > 1 &&
+              gcd(yellowstoneList.last, num) == 1) {
+            yellowstoneList = yellowstoneList :+ num
+            num += 1
+            // break the inner while loop
+            break
+          }
+          notYellowstoneList = notYellowstoneList :+ num
+          num += 1
+        }
+        });
+      }
+    }
+    yellowstoneList
+  }
+
+  def gcd(a: Int, b: Int): Int = if (b == 0) a else gcd(b, a % b)
+}

Task/Yellowstone-sequence/Wren/yellowstone-sequence.wren

@@ -1,4 +1,4 @@
-import "/math" for Int
+import "./math" for Int
 
 var yellowstone = Fn.new { |n|
     var m = {}