Data update

Task/Sorting-algorithms-Permutation-sort/Pluto/sorting-algorithms-permutation-sort.pluto

@@ -0,0 +1,24 @@
+local function is_sorted(a)
+    for i = 1, #a - 1 do
+        if a[i] > a[i + 1] then return false end
+    end
+    return true
+end
+
+local a = {170, 45, 75, -90, -802, 24, 2, 66}
+
+-- Recursive permutation generator.
+local function recurse(last)
+    if last <= 1 then return is_sorted(a) end
+    for i = 1, last do
+        a[i], a[last] = a[last], a[i]
+        if recurse(last - 1) then return true end
+        a[i], a[last] = a[last], a[i]
+    end
+    return false
+end
+
+print($"Unsorted: \{{a:concat(", ")}}")
+local c = #a
+if c > 1 and !recurse(c) then error("Sorted permutation not found!") end
+print($"Sorted  : \{{a:concat(", ")}}")