Added unit test.
Project: http://git-wip-us.apache.org/repos/asf/commons-math/repo Commit: http://git-wip-us.apache.org/repos/asf/commons-math/commit/80814930 Tree: http://git-wip-us.apache.org/repos/asf/commons-math/tree/80814930 Diff: http://git-wip-us.apache.org/repos/asf/commons-math/diff/80814930 Branch: refs/heads/develop Commit: 808149305ba26224917e29aa0c0089701bd91936 Parents: 7a8dc00 Author: Gilles <er...@apache.org> Authored: Sun Mar 13 03:05:54 2016 +0100 Committer: Gilles <er...@apache.org> Committed: Mon Mar 21 00:36:55 2016 +0100 ---------------------------------------------------------------------- .../apache/commons/math4/util/MathArraysTest.java | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/commons-math/blob/80814930/src/test/java/org/apache/commons/math4/util/MathArraysTest.java ---------------------------------------------------------------------- diff --git a/src/test/java/org/apache/commons/math4/util/MathArraysTest.java b/src/test/java/org/apache/commons/math4/util/MathArraysTest.java index a6cc764..e71a824 100644 --- a/src/test/java/org/apache/commons/math4/util/MathArraysTest.java +++ b/src/test/java/org/apache/commons/math4/util/MathArraysTest.java @@ -1107,6 +1107,23 @@ public class MathArraysTest { } @Test + public void testShuffleNoDuplicates() { + final int n = 100; + final int[] orig = MathArrays.natural(n); + MathArrays.shuffle(orig); + + // Test that all (unique) entries exist in the shuffled array. + final int[] count = new int[n]; + for (int i = 0; i < n; i++) { + count[orig[i]] += 1; + } + + for (int i = 0; i < n; i++) { + Assert.assertEquals(1, count[i]); + } + } + + @Test public void testShuffleTail() { final int[] orig = new int[] { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 }; final int[] list = orig.clone();
