Added selectRandomSubset() which selects a random subset of elements (with

equal probability) from a collection. git-svn-id: https://samskivert.googlecode.com/svn/trunk@701 6335cc39-0255-0410-8fd6-9bcaacd3b74c
2002-04-11 04:11:23 +00:00
parent 8daf88066b
commit 6caf731ff9
2 changed files with 102 additions and 1 deletions
@@ -0,0 +1,46 @@
+//
+// $Id: CollectionUtilTest.java,v 1.1 2002/04/11 04:11:23 mdb Exp $
+
+package com.samskivert.util;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import junit.framework.Test;
+import junit.framework.TestCase;
+
+/**
+ * Tests the {@link CollectionUtil} class.
+ */
+public class CollectionUtilTest extends TestCase
+{
+    public CollectionUtilTest ()
+    {
+        super(CollectionUtil.class.getName());
+    }
+
+    public void runTest ()
+    {
+        ArrayList list = new ArrayList();
+        for (int i = 0; i < 100; i++) {
+            list.add(new Integer(i));
+        }
+
+        for (int i = 0; i < 10; i++) {
+            List subset = CollectionUtil.selectRandomSubset(list, 10);
+            // System.out.println(StringUtil.toString(subset));
+            assertTrue("length == 10", subset.size() == 10);
+        }
+    }
+
+    public static Test suite ()
+    {
+        return new CollectionUtilTest();
+    }
+
+    public static void main (String[] args)
+    {
+        CollectionUtilTest test = new CollectionUtilTest();
+        test.runTest();
+    }
+}