From 63c3043200de6b28a8c192f1b5625940435ea55e Mon Sep 17 00:00:00 2001
From: Jed Barber <jjbarber@y7mail.com>
Date: Sat, 17 Oct 2015 14:20:48 +1100
Subject: Organised source code a bit, added makefile with clean target

---
 sort/quick.adb | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)
 create mode 100644 sort/quick.adb

(limited to 'sort/quick.adb')

diff --git a/sort/quick.adb b/sort/quick.adb
new file mode 100644
index 0000000..4586b3b
--- /dev/null
+++ b/sort/quick.adb
@@ -0,0 +1,49 @@
+
+
+package body Quick is
+
+
+    procedure Swap(A, B : in out Element_T) is
+        Temp : Element_T;
+    begin
+        Temp := A;
+        A := B;
+        B := Temp;
+    end Swap;
+
+
+    procedure In_Place(Arr : in out Array_T) is
+        Pivot, Left, Right : Index_T;
+    begin
+        if Arr'Length <= 1 then
+            return;
+        end if;
+
+        Pivot := Arr'First;
+        Left := Index_T'Succ(Pivot);
+        Right := Arr'Last;
+
+        loop
+            while not (Arr(Left) > Arr(Pivot)) and Left < Arr'Last loop
+                Left := Index_T'Succ(Left);
+            end loop;
+            while Arr(Right) > Arr(Pivot) and Right > Arr'First loop
+                Right := Index_T'Pred(Right);
+            end loop;
+            exit when Left >= Right;
+            Swap(Arr(Left), Arr(Right));
+        end loop;
+
+        Swap(Arr(Pivot), Arr(Right));
+
+        if Right > Arr'First then
+            In_Place( Arr(Arr'First .. Index_T'Pred(Right)) );
+        end if;
+        if Right < Arr'Last then
+            In_Place( Arr(Index_T'Succ(Right) .. Arr'Last) );
+        end if;
+    end In_Place;
+
+
+end Quick;
+
-- 
cgit