vavr-io / vavr-benchmark Goto Github PK

public static <T> Array<Array<T>> permOld(Array<T> array) {
    if (array.isEmpty()) {
        return Array.empty();
    } else {
        final Array<T> tail = array.tail();
        if (tail.isEmpty()) {
            return Array.of(array);
        } else {
            final Array<Array<T>> zero = Array.empty();
            return array.distinct().foldLeft(zero, (xs, x) -> {
                final Function<Array<T>, Array<T>> prepend = l -> l.prepend(x);
                return xs.appendAll(array.remove(x).permutations().map(prepend));
            });
        }
    }
}

public static <T> Array<Array<T>> permNew(Array<T> array) {
    if (array.isEmpty()) {
        return Array.empty();
    } else {
        Array<Array<T>> results = Array.empty();
        for (T t : array.distinct()) {
            for (Array<T> ts : array.remove(t).permutations()) {
                results = results.append(Array.of(t).appendAll(ts));
            }
        }
        return results;
    }
}

// AbstractTraversableTest
@Test
public void shouldTakeNoneOnNil() {
    if (useIsEqualToInsteadOfIsSameAs()) {
        assertThat(empty().take(1)).isEqualTo(empty());
    } else {
        assertThat(empty().take(1)).isSameAs(empty());
    }
}

// PriorityQueue (current)
@Override
public PriorityQueue<T> take(int n) {
    return ofAll(comparator, iterator().take(n));
}

// PriorityQueue (time and mem saver)
@Override
public PriorityQueue<T> take(int n) {
    if (n <= 0) {
        return this;
    } else if (n >= size()) {
        return empty(comparator());
    } else {
        return ofAll(comparator, iterator().take(n));
    }
}