all tasks

Task/Sorting-algorithms-Quicksort/SETL/sorting-algorithms-quicksort-1.setl

@@ -0,0 +1,22 @@
+a := [2,5,8,7,0,9,1,3,6,4];
+qsort(a);
+print(a);
+
+proc qsort(rw a);
+  if #a > 1 then
+    pivot := a(#a div 2 + 1);
+    l := 1;
+    r := #a;
+    (while l < r)
+      (while a(l) < pivot) l +:= 1; end;
+      (while a(r) > pivot) r -:= 1; end;
+      swap(a(l), a(r));
+    end;
+    qsort(a(1..l-1));
+    qsort(a(r+1..#a));
+  end if;
+end proc;
+
+proc swap(rw x, rw y);
+  [y,x] := [x,y];
+end proc;

Task/Sorting-algorithms-Quicksort/SETL/sorting-algorithms-quicksort-2.setl

@@ -0,0 +1,12 @@
+a := [2,5,8,7,0,9,1,3,6,4];
+print(qsort(a));
+
+proc qsort(a);
+  if #a > 1 then
+    pivot := a(#a div 2 + 1);
+    a := qsort([x in a | x < pivot]) +
+         [x in a | x = pivot] +
+         qsort([x in a | x > pivot]);
+  end if;
+  return a;
+end proc;