TWC268

1 files changed, 31 insertions, 0 deletions

diff --git a/challenge-268/deadmarshal/modula-3/ch2/src/Sorting.mg b/challenge-268/deadmarshal/modula-3/ch2/src/Sorting.mg
new file mode 100644
index 0000000000..cf0dbd6b4a
--- /dev/null
+++ b/challenge-268/deadmarshal/modula-3/ch2/src/Sorting.mg
@@ -0,0 +1,31 @@
+GENERIC MODULE Sorting(Elem);
+
+PROCEDURE Swap(VAR A,B:Elem.T) =
+  VAR Temp:Elem.T := A;
+  BEGIN
+    A := B;
+    B := Temp
+  END Swap;
+  
+PROCEDURE QuickSort(VAR A:ARRAY OF Elem.T;Left,Right:INTEGER) =
+  VAR
+    I,J:INTEGER;
+    Pivot:Elem.T;
+  BEGIN
+    I := Left; J := Right;
+    Pivot := A[(Left+Right) DIV 2];
+    REPEAT
+      WHILE Elem.Compare(Pivot,A[I]) > 0 DO INC(I) END;
+      WHILE Elem.Compare(Pivot,A[J]) < 0 DO DEC(J) END;
+      IF I <= J THEN
+        Swap(A[I],A[J]);
+        INC(I); DEC(J)
+      END;
+    UNTIL I > J;
+    IF Left < J THEN QuickSort(A,Left,J) END;
+    IF I < Right THEN QuickSort(A,I,Right) END
+  END QuickSort;
+   
+BEGIN
+END Sorting.
+