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copied!<p><strong>EDIT:</strong> As FearUs pointed out, a better solution is to use Guava's <a href="https://google.github.io/guava/releases/19.0/api/docs/com/google/common/collect/Sets.html#powerSet(java.util.Set)" rel="noreferrer">Sets.powerset(Set set)</a>.</p> <p><strong>EDIT 2:</strong> Updated links.</p> <hr> <p>Quick and dirty translation of <a href="http://web.archive.org/web/20100206003803/http://davidtran.doublegifts.com/blog/?p=144" rel="noreferrer">this solution</a>:</p> <pre><code>public static void main(String[] args) { List<List<String>> powerSet = new LinkedList<List<String>>(); for (int i = 1; i <= args.length; i++) powerSet.addAll(combination(Arrays.asList(args), i)); System.out.println(powerSet); } public static <T> List<List<T>> combination(List<T> values, int size) { if (0 == size) { return Collections.singletonList(Collections.<T> emptyList()); } if (values.isEmpty()) { return Collections.emptyList(); } List<List<T>> combination = new LinkedList<List<T>>(); T actual = values.iterator().next(); List<T> subSet = new LinkedList<T>(values); subSet.remove(actual); List<List<T>> subSetCombination = combination(subSet, size - 1); for (List<T> set : subSetCombination) { List<T> newSet = new LinkedList<T>(set); newSet.add(0, actual); combination.add(newSet); } combination.addAll(combination(subSet, size)); return combination; } </code></pre> <p>Test:</p> <pre><code>$ java PowerSet ted williams golden [[ted], [williams], [golden], [ted, williams], [ted, golden], [williams, golden], [ted, williams, golden]] $ </code></pre>

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