@Test
public void test_simple_with_equal_elements_permutation() {
List<List<Integer>> permutations =
Generator.permutation(Arrays.asList(1, 2, 2, 3))
.simple()
.stream()
.collect(Collectors.<List<Integer>>toList());
assertThat(permutations).hasSize(12);
System.out.println("Identical permutations of (1, 2, 2, 3):");
permutations.stream().forEach(System.out::println);
assertThat(permutations.get(0)).containsExactly(1, 2, 2, 3);
assertThat(permutations.get(1)).containsExactly(1, 2, 3, 2);
assertThat(permutations.get(2)).containsExactly(1, 3, 2, 2);
assertThat(permutations.get(3)).containsExactly(2, 1, 2, 3);
assertThat(permutations.get(4)).containsExactly(2, 1, 3, 2);
assertThat(permutations.get(5)).containsExactly(2, 2, 1, 3);
assertThat(permutations.get(6)).containsExactly(2, 2, 3, 1);
assertThat(permutations.get(7)).containsExactly(2, 3, 1, 2);
assertThat(permutations.get(8)).containsExactly(2, 3, 2, 1);
assertThat(permutations.get(9)).containsExactly(3, 1, 2, 2);
assertThat(permutations.get(10)).containsExactly(3, 2, 1, 2);
assertThat(permutations.get(11)).containsExactly(3, 2, 2, 1);
}
@Test
public void test_simple_empty_permutation() {
List<List<Integer>> permutations =
Generator.permutation(new Integer[] {})
.simple()
.stream()
.collect(Collectors.<List<Integer>>toList());
assertThat(permutations).isEmpty();
}
@Test
public void test_simple_permutations_iterator_toString() {
Iterator<List<Integer>> permutations =
Generator.permutation(Arrays.asList(1, 2, 3)).simple().iterator();
assertThat(permutations).isNotNull();
assertThat(permutations.hasNext()).isTrue();
assertThat(permutations.next()).containsExactly(1, 2, 3);
assertThat(permutations.toString()).isEqualTo("SimplePermutationIterator=[#1, [1, 2, 3]]");
}
@Test(expected = UnsupportedOperationException.class)
public void test_duplicated_permutation_iterator_remove_operation() {
Iterator<List<Integer>> permutations =
Generator.permutation(Arrays.asList(1, 2, 2)).simple().iterator();
assertThat(permutations).isNotNull();
assertThat(permutations.hasNext()).isTrue();
// this method should throw a UnsupportedOperationException
permutations.remove();
}
@Test
public void test_simple_one_permutation() {
List<List<Integer>> permutations =
Generator.permutation(1).simple().stream().collect(Collectors.<List<Integer>>toList());
assertThat(permutations).hasSize(1);
System.out.println("Simple one permutations of (1):");
permutations.stream().forEach(System.out::println);
assertThat(permutations.get(0)).containsOnly(1);
}
@Test
public void test_all_identical_permutation() {
List<List<String>> permutations =
Generator.permutation("a", "a", "a")
.simple()
.stream()
.collect(Collectors.<List<String>>toList());
assertThat(permutations).hasSize(1);
System.out.println("Identical permutations of (a, a, a):");
permutations.stream().forEach(System.out::println);
assertThat(permutations.get(0)).containsExactly("a", "a", "a");
}
@Test
public void test_identical_permutation_treat_as_different() {
List<List<String>> permutations =
Generator.permutation("a", "a", "b")
.simple(PermutationGenerator.TreatDuplicatesAs.DIFFERENT)
.stream()
.collect(Collectors.<List<String>>toList());
assertThat(permutations).hasSize(3);
System.out.println("Identical permutations of (a, a, b):");
permutations.stream().forEach(System.out::println);
assertThat(permutations.get(0)).containsExactly("a", "a", "b");
assertThat(permutations.get(1)).containsExactly("a", "b", "a");
assertThat(permutations.get(2)).containsExactly("b", "a", "a");
}
@Test
public void test_any_expression_permutation() {
List<List<String>> permutations =
Generator.permutation(new String[] {"x", "x^2", "x+1"})
.simple()
.stream()
.collect(Collectors.<List<String>>toList());
assertThat(permutations).hasSize(6);
System.out.println("Identical permutations of (x, x^2, x+1):");
permutations.stream().forEach(System.out::println);
assertThat(permutations.get(0)).containsExactly("x", "x^2", "x+1");
assertThat(permutations.get(1)).containsExactly("x", "x+1", "x^2");
assertThat(permutations.get(2)).containsExactly("x+1", "x", "x^2");
assertThat(permutations.get(3)).containsExactly("x+1", "x^2", "x");
assertThat(permutations.get(4)).containsExactly("x^2", "x+1", "x");
assertThat(permutations.get(5)).containsExactly("x^2", "x", "x+1");
}
@Test
public void test_abc_permutation() {
List<List<String>> permutations =
Generator.permutation(Arrays.asList("a", "b", "c"))
.simple()
.stream()
.collect(Collectors.<List<String>>toList());
assertThat(permutations).hasSize(6);
System.out.println("Identical permutations of (a, b, c):");
permutations.stream().forEach(System.out::println);
assertThat(permutations.get(0)).containsExactly("a", "b", "c");
assertThat(permutations.get(1)).containsExactly("a", "c", "b");
assertThat(permutations.get(2)).containsExactly("c", "a", "b");
assertThat(permutations.get(3)).containsExactly("c", "b", "a");
assertThat(permutations.get(4)).containsExactly("b", "c", "a");
assertThat(permutations.get(5)).containsExactly("b", "a", "c");
}
@Test
public void test_simple_permutation() {
List<List<Integer>> permutations =
Generator.permutation(1, 2, 3)
.simple()
.stream()
.collect(Collectors.<List<Integer>>toList());
assertThat(permutations).hasSize(6);
System.out.println("Simple permutations of (1, 2, 3):");
permutations.stream().forEach(System.out::println);
assertThat(permutations.get(0)).containsExactly(1, 2, 3);
assertThat(permutations.get(1)).containsExactly(1, 3, 2);
assertThat(permutations.get(2)).containsExactly(3, 1, 2);
assertThat(permutations.get(3)).containsExactly(3, 2, 1);
assertThat(permutations.get(4)).containsExactly(2, 3, 1);
assertThat(permutations.get(5)).containsExactly(2, 1, 3);
}
@Test
public void test_all_identical_permutation_treat_as_identical() {
List<List<String>> permutations =
Generator.permutation("x", "x", "x")
.simple(PermutationGenerator.TreatDuplicatesAs.IDENTICAL)
.stream()
.collect(Collectors.<List<String>>toList());
assertThat(permutations).hasSize(6);
System.out.println("Identical permutations of (x, x, x):");
permutations.stream().forEach(System.out::println);
assertThat(permutations.get(0)).containsExactly("x", "x", "x");
assertThat(permutations.get(1)).containsExactly("x", "x", "x");
assertThat(permutations.get(2)).containsExactly("x", "x", "x");
assertThat(permutations.get(3)).containsExactly("x", "x", "x");
assertThat(permutations.get(4)).containsExactly("x", "x", "x");
assertThat(permutations.get(5)).containsExactly("x", "x", "x");
}
