public void testOrderedPermutationSetSizeOverflow() {
// 12 elements won't overflow
assertEquals(
479001600 /*12!*/,
Collections2.orderedPermutations(newArrayList(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12))
.size());
// 13 elements overflow an int
assertEquals(
Integer.MAX_VALUE,
Collections2.orderedPermutations(newArrayList(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13))
.size());
// 21 elements overflow a long
assertEquals(
Integer.MAX_VALUE,
Collections2.orderedPermutations(
newArrayList(
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21))
.size());
// Almost force an overflow in the binomial coefficient calculation
assertEquals(
1391975640 /*C(34,14)*/,
Collections2.orderedPermutations(concat(nCopies(20, 1), nCopies(14, 2))).size());
// Do force an overflow in the binomial coefficient calculation
assertEquals(
Integer.MAX_VALUE,
Collections2.orderedPermutations(concat(nCopies(21, 1), nCopies(14, 2))).size());
}
public void testOrderedPermutationSetRepeatedElementsSize() {
List<Integer> list = newArrayList(1, 1, 1, 1, 2, 2, 3);
Collection<List<Integer>> permutations =
Collections2.orderedPermutations(list, Ordering.natural());
assertPermutationsCount(105, permutations);
}
public void testOrderedPermutationSetOneElement() {
List<Integer> list = newArrayList(1);
Iterator<List<Integer>> permutations = Collections2.orderedPermutations(list).iterator();
assertNextPermutation(newArrayList(1), permutations);
assertNoMorePermutations(permutations);
}
public void testPermutationSetSizeOverflow() {
// 13 elements overflow an int
assertEquals(
Integer.MAX_VALUE,
Collections2.permutations(newArrayList(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)).size());
// 21 elements overflow a long
assertEquals(
Integer.MAX_VALUE,
Collections2.orderedPermutations(
newArrayList(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20))
.size());
assertEquals(
Integer.MAX_VALUE,
Collections2.orderedPermutations(
newArrayList(
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21))
.size());
}
public void testOrderedPermutationSetContains() {
List<Integer> list = newArrayList(3, 2, 1);
Collection<List<Integer>> permutationSet = Collections2.orderedPermutations(list);
assertTrue(permutationSet.contains(newArrayList(1, 2, 3)));
assertTrue(permutationSet.contains(newArrayList(2, 3, 1)));
assertFalse(permutationSet.contains(newArrayList(1, 2)));
assertFalse(permutationSet.contains(newArrayList(1, 1, 2, 3)));
assertFalse(permutationSet.contains(newArrayList(1, 2, 3, 4)));
assertFalse(permutationSet.contains(null));
}
public void testOrderedPermutationSetThreeElements() {
List<String> list = newArrayList("b", "a", "c");
Iterator<List<String>> permutations = Collections2.orderedPermutations(list).iterator();
assertNextPermutation(newArrayList("a", "b", "c"), permutations);
assertNextPermutation(newArrayList("a", "c", "b"), permutations);
assertNextPermutation(newArrayList("b", "a", "c"), permutations);
assertNextPermutation(newArrayList("b", "c", "a"), permutations);
assertNextPermutation(newArrayList("c", "a", "b"), permutations);
assertNextPermutation(newArrayList("c", "b", "a"), permutations);
assertNoMorePermutations(permutations);
}
public void testOrderedPermutationSetEmpty() {
List<Integer> list = newArrayList();
Collection<List<Integer>> permutationSet = Collections2.orderedPermutations(list);
assertEquals(1, permutationSet.size());
ASSERT.that(permutationSet).has().item(list);
Iterator<List<Integer>> permutations = permutationSet.iterator();
assertNextPermutation(Lists.<Integer>newArrayList(), permutations);
assertNoMorePermutations(permutations);
}
public void testOrderedPermutationSetRepeatedElements() {
List<Integer> list = newArrayList(1, 1, 2, 2);
Iterator<List<Integer>> permutations =
Collections2.orderedPermutations(list, Ordering.natural()).iterator();
assertNextPermutation(newArrayList(1, 1, 2, 2), permutations);
assertNextPermutation(newArrayList(1, 2, 1, 2), permutations);
assertNextPermutation(newArrayList(1, 2, 2, 1), permutations);
assertNextPermutation(newArrayList(2, 1, 1, 2), permutations);
assertNextPermutation(newArrayList(2, 1, 2, 1), permutations);
assertNextPermutation(newArrayList(2, 2, 1, 1), permutations);
assertNoMorePermutations(permutations);
}
