September Morn Update

Task/Permutations/Modula-3/permutations-4.mod3

@@ -0,0 +1,43 @@
+MODULE GPermutations EXPORTS Main;
+
+IMPORT IO, IntSeq, IntSetTree, IntSeqSeq, IntPermutations;
+
+CONST
+
+  n = 7;
+
+VAR
+
+  chosen: IntSeq.T;
+  remaining: IntSetTree.T;
+  result: IntSeqSeq.T;
+
+PROCEDURE Factorial(n: CARDINAL): CARDINAL =
+VAR result := 1;
+BEGIN
+  FOR i := 2 TO n DO
+    result := result * i;
+  END;
+  RETURN result;
+END Factorial;
+
+BEGIN
+
+  (* initial setup *)
+  chosen := NEW(IntSeq.T).init(n);
+  remaining := NEW(IntSetTree.T).init();
+  result := NEW(IntSeqSeq.T).init(Factorial(n));
+  FOR i := 1 TO n DO EVAL remaining.insert(i); END;
+
+  IntPermutations.GeneratePermutations(chosen, remaining, result);
+
+  IO.Put("Printing "); IO.PutInt(result.size());
+  IO.Put(" permutations of "); IO.PutInt(n); IO.Put(" elements \n");
+  FOR i := 0 TO result.size() - 1 DO
+    FOR j := 0 TO result.get(i).size() - 1 DO
+      IO.PutInt(result.get(i).get(j)); IO.PutChar(' ');
+    END;
+    IO.PutChar('\n');
+  END;
+
+END GPermutations.