| // Copyright (c) 2018, the Dart project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| |
| /// @assertion void shuffle([Random random]) |
| /// Shuffles the elements of this list randomly. |
| /// @description Checks that [this] is shuffled randomly. Use a Random seed |
| /// @author sgrekhov@unipro.ru |
| |
| import "dart:typed_data"; |
| import "dart:math"; |
| import "../../../Utils/expect.dart"; |
| |
| f64x2(x, y) => new Float64x2(x, y); |
| |
| bool isOrderChanged(List<Float64x2> list, Float64x2List sl) { |
| Expect.equals(list.length, sl.length); |
| bool moved = false; |
| for (int i = 0; i < list.length; i++) { |
| bool found = false; |
| for (int j = 0; j < list.length; j++) { |
| if (list[i].x == sl[j].x && list[i].y == sl[j].y) { |
| found = true; |
| if (i != j) moved = true; |
| break; |
| } |
| } |
| Expect.isTrue(found, "Element ${list[i]} not found in shuffled list"); |
| } |
| return moved; |
| } |
| |
| main() { |
| List<Float64x2> list = [ |
| f64x2(1.0, 2.0), f64x2(2.0, 3.0), f64x2(3.0, 4.0), f64x2(4.0, 5.0), |
| f64x2(5.0, 6.0), f64x2(6.0, 7.0), f64x2(7.0, 8.0), f64x2(8.0, 9.0), |
| f64x2(9.0, 10.0), f64x2(10.0, 11.0) |
| ]; |
| |
| var counter = 0; |
| for (int i = 0; i < 10; i++) { |
| var sl = new Float64x2List.fromList(list); |
| sl.shuffle(new Random()); |
| if (!isOrderChanged(list, sl)) { |
| counter++; |
| } |
| } |
| /* We allow a couple of shuffles return data in the same order */ |
| Expect.isTrue(counter < 3); |
| } |