Another update from ingydotnet^djgoku

Task/Sorting-algorithms-Bogosort/Eiffel/sorting-algorithms-bogosort-1.e

@@ -1,17 +1,23 @@
 class
 	BOGO_SORT
+
 feature
-	bogo_sort(ar: ARRAY[INTEGER]): ARRAY[INTEGER]
-	do
-		from
-		until
-			is_sorted (ar) = TRUE
-		loop
-			Result:= shuffel(ar)
+
+	bogo_sort (ar: ARRAY [INTEGER]): ARRAY [INTEGER]
+			-- Sorted array in ascending order.
+		do
+			from
+			until
+				is_sorted (ar) = True
+			loop
+				Result := shuffel (ar)
+			end
 		end
-	end
-feature{NONE}
-	is_sorted (ar:ARRAY[INTEGER]): BOOLEAN
+
+feature {NONE}
+
+	is_sorted (ar: ARRAY [INTEGER]): BOOLEAN
+			-- Is 'ar' sorted in ascending order?
 		require
 			not_void: ar /= Void
 		local
@@ -19,7 +25,7 @@ feature{NONE}
 		do
 			Result := True
 			from
-				i := 1+ 1
+				i := 1 + 1
 			invariant
 				i >= 1 + 1 and i <= ar.count + 1
 			until
@@ -32,27 +38,29 @@ feature{NONE}
 			end
 		end
 
-	shuffel(ar:ARRAY[INTEGER]): ARRAY[INTEGER]
-	        require
-		        not_void: ar/= Void
-	        local
-		        i,j:INTEGER
-		        ith: INTEGER
-		        random: V_RANDOM
-	        do
-	        	create random
-		        from
-			        i:=ar.count
-		        until
-			        i<2
-		        loop
-			        j:=random.bounded_item (1, i)
-			        ith:= ar[i]
-			        ar[i]:= ar[j]
-			        ar[j]:= ith
-			        random.forth
-			        i:=i-1
-		        end
-		        Result:= ar
-	        end
+	shuffle (ar: ARRAY [INTEGER]): ARRAY [INTEGER]
+			-- Array containing the same elements as 'ar' in a shuffled order.
+		require
+			more_than_one_element: ar.count > 1
+		local
+			count, j, ith: INTEGER
+			random: V_RANDOM
+		do
+			create random
+			create Result.make_empty
+			Result.deep_copy (ar)
+			count := ar.count
+			across
+				1 |..| count as c
+			loop
+				j := random.bounded_item (c.item, count)
+				ith := Result [c.item]
+				Result [c.item] := Result [j]
+				Result [j] := ith
+				random.forth
+			end
+		ensure
+			same_elements: across ar as a all Result.has (a.item) end
+		end
+
 end

Task/Sorting-algorithms-Bogosort/Eiffel/sorting-algorithms-bogosort-2.e

@@ -1,24 +1,32 @@
 class
 	APPLICATION
 
-inherit
-	ARGUMENTS
-
 create
 	make
 
-feature {NONE} -- Initialization
+feature {NONE}
 
 	make
 		do
-			test:= <<3,2,5,7,1>>
+			test := <<3, 2, 5, 7, 1>>
 			io.put_string ("Unsorted: ")
-			across test as t loop io.put_string (t.item.out + " ") end
+			across
+				test as t
+			loop
+				io.put_string (t.item.out + " ")
+			end
 			create sorter
-			test:= sorter.bogo_sort (test)
+			test := sorter.bogo_sort (test)
 			io.put_string ("%NSorted: ")
-			across test as t loop io.put_string (t.item.out + " ") end
+			across
+				test as t
+			loop
+				io.put_string (t.item.out + " ")
+			end
 		end
-	test: ARRAY[INTEGER]
-        sorter: BOGO_SORT
+
+	test: ARRAY [INTEGER]
+
+	sorter: BOGO_SORT
+
 end