Another update from ingydotnet^djgoku

Task/Sorting-algorithms-Counting-sort/Eiffel/sorting-algorithms-counting-sort-1.e

@@ -1,34 +1,69 @@
 class
 	COUNTING_SORT
+
 feature
-sort(ar: ARRAY[INTEGER]; min, max: INTEGER): ARRAY[INTEGER]
-	local
-		count: ARRAY[INTEGER]
-		i, j, z: INTEGER
-	do
-		create count.make_filled (0, 0, max-min)
-		from
-			i:= 0
-		until
-			i= ar.count
-		loop
-			count[ar[i]-min]:= count[ar[i]-min]+1
-			i:= i+1
-		end
-		across count as c loop io.put_string (c.item.out + "%T")  end
-		z:= 0
-		from i:= min
-		until i>max
-		loop
-			from j:= 0
-			until j= count[i-min]
+
+	sort (ar: ARRAY [INTEGER]; min, max: INTEGER): ARRAY [INTEGER]
+			-- Sorted Array in ascending order.
+		require
+			ar_not_void: ar /= Void
+			lowest_index_zero: ar.lower = 0
+		local
+			count: ARRAY [INTEGER]
+			i, j, z: INTEGER
+		do
+			create Result.make_empty
+			Result.deep_copy (ar)
+			create count.make_filled (0, 0, max - min)
+			from
+				i := 0
+			until
+				i = Result.count
 			loop
-				ar[z]:=i
-				z:= z+1
-				j:= j+1
+				count [Result [i] - min] := count [Result [i] - min] + 1
+				i := i + 1
 			end
-			i:= i+1
+			z := 0
+			from
+				i := min
+			until
+				i > max
+			loop
+				from
+					j := 0
+				until
+					j = count [i - min]
+				loop
+					Result [z] := i
+					z := z + 1
+					j := j + 1
+				end
+				i := i + 1
+			end
+		ensure
+			Result_is_sorted: is_sorted (Result)
 		end
-		Result:= ar
-	end
+
+feature {NONE}
+
+	is_sorted (ar: ARRAY [INTEGER]): BOOLEAN
+			--- Is 'ar' sorted in ascending order?
+		require
+			ar_not_empty: ar.is_empty = False
+		local
+			i: INTEGER
+		do
+			Result := True
+			from
+				i := ar.lower
+			until
+				i = ar.upper
+			loop
+				if ar [i] > ar [i + 1] then
+					Result := False
+				end
+				i := i + 1
+			end
+		end
+
 end

Task/Sorting-algorithms-Counting-sort/Eiffel/sorting-algorithms-counting-sort-2.e

@@ -1,24 +1,39 @@
 class
 	APPLICATION
-inherit
-	ARGUMENTS
+
 create
-        make
-feature
 	make
-	do
-		create test.make_filled(0,0,5)
-		test[0]:=-7
-		test[1]:=4
-		test[2]:=2
-		test[3]:=6
-		test[4]:=1
-		test[5]:=3
-		across test as t  loop io.put_string (t.item.out + "%T")  end
-		create count
-		test:=count.sort (test, -7, 6)
-		across test as ar loop io.put_string (ar.item.out+"%T")  end
-	end
+
+feature
+
+	make
+		do
+			create test.make_filled (0, 0, 5)
+			test [0] := -7
+			test [1] := 4
+			test [2] := 2
+			test [3] := 6
+			test [4] := 1
+			test [5] := 3
+			io.put_string ("unsorted:%N")
+			across
+				test as t
+			loop
+				io.put_string (t.item.out + "%T")
+			end
+			io.new_line
+			io.put_string ("sorted:%N")
+			create count
+			test := count.sort (test, -7, 6)
+			across
+				test as ar
+			loop
+				io.put_string (ar.item.out + "%T")
+			end
+		end
+
 	count: COUNTING_SORT
-	test: ARRAY[INTEGER]
+
+	test: ARRAY [INTEGER]
+
 end