Data update

Task/Topswops/Ada/topswops.adb

@@ -0,0 +1,39 @@
+with Ada.Integer_Text_IO, Generic_Perm;
+
+procedure Topswaps is
+
+   function Topswaps(Size: Positive) return Natural is
+      package Perms is new Generic_Perm(Size);
+      P: Perms.Permutation;
+      Done: Boolean;
+      Max: Natural;
+
+      function Swapper_Calls(P: Perms.Permutation) return Natural is
+	 Q: Perms.Permutation := P;
+	 I: Perms.Element := P(1);
+      begin
+	 if I = 1 then
+	    return 0;
+	 else
+	    for Idx in 1 .. I loop
+	       Q(Idx) := P(I-Idx+1);
+	    end loop;
+	    return 1 + Swapper_Calls(Q);
+	 end if;
+      end Swapper_Calls;
+
+   begin
+      Perms.Set_To_First(P, Done);
+      Max:= Swapper_Calls(P);
+      while not Done loop
+	 Perms.Go_To_Next(P, Done);
+	 Max := natural'Max(Max, Swapper_Calls(P));
+      end loop;
+      return Max;
+   end Topswaps;
+
+begin
+   for I in 1 .. 10 loop
+      Ada.Integer_Text_IO.Put(Item => Topswaps(I), Width => 3);
+   end loop;
+end Topswaps;

Task/Topswops/EasyLang/topswops.easy

@@ -0,0 +1,30 @@
+global n d best[] .
+#
+proc tryswaps &a[] f .
+   if d > best[n] : best[n] = d
+   for s = len a[] downto 1
+      if a[s] = 0 or a[s] = s : break 1
+      if d + best[s] <= best[n] : return
+   .
+   d += 1
+   for i = 1 to s : b[] &= a[i]
+   k = 1
+   for i = 2 to s
+      k *= 2
+      if b[i] = 0 and bitand f k = 0 or b[i] = i
+         b[1] = i
+         for j = i - 1 downto 1
+            b[i - j + 1] = a[j]
+         .
+         tryswaps b[] (bitor f k)
+      .
+   .
+   d -= 1
+.
+for n = 1 to 10
+   best[] &= 0
+   x[] &= 0
+   d = 0
+   tryswaps x[] 1
+   print n & ": " & best[n]
+.

Task/Topswops/JavaScript/topswops.js

@@ -0,0 +1,56 @@
+class Topswops {
+    static maxBest = 32;
+    static best = new Array(Topswops.maxBest).fill(0);
+
+    static trySwaps(deck, f, d, n) {
+        if (d > this.best[n]) {
+            this.best[n] = d;
+        }
+        for (let i = n - 1; i >= 0; i--) {
+            if (deck[i] === -1 || deck[i] === i) {
+                break;
+            }
+            if (d + this.best[i] <= this.best[n]) {
+                return;
+            }
+        }
+        let deck2 = [...deck];
+        for (let i = 1; i < n; i++) {
+            const k = 1 << i;
+            if (deck2[i] === -1) {
+                if ((f & k) !== 0) {
+                    continue;
+                }
+            } else if (deck2[i] !== i) {
+                continue;
+            }
+            deck2[0] = i;
+            for (let j = i - 1; j >= 0; j--) {
+                deck2[i - j] = deck[j]; // Reverse copy.
+            }
+            this.trySwaps(deck2, f | k, d + 1, n);
+        }
+    }
+
+    static topswops(n) {
+        if (n <= 0 || n >= this.maxBest) {
+            throw new Error("n must be between 1 and maxBest");
+        }
+        this.best[n] = 0;
+        let deck0 = new Array(n + 1).fill(0);
+        for (let i = 1; i < n; i++) {
+            deck0[i] = -1;
+        }
+        this.trySwaps(deck0, 1, 0, n);
+        return this.best[n];
+    }
+
+    static main() {
+        for (let i = 1; i < 11; i++) {
+            console.log(`${i}: ${this.topswops(i)}`);
+        }
+    }
+}
+
+// Run the main function
+Topswops.main();