Server : Apache/2.4.41 (Ubuntu) System : Linux absol.cf 5.4.0-198-generic #218-Ubuntu SMP Fri Sep 27 20:18:53 UTC 2024 x86_64 User : www-data ( 33) PHP Version : 7.4.33 Disable Function : pcntl_alarm,pcntl_fork,pcntl_waitpid,pcntl_wait,pcntl_wifexited,pcntl_wifstopped,pcntl_wifsignaled,pcntl_wifcontinued,pcntl_wexitstatus,pcntl_wtermsig,pcntl_wstopsig,pcntl_signal,pcntl_signal_get_handler,pcntl_signal_dispatch,pcntl_get_last_error,pcntl_strerror,pcntl_sigprocmask,pcntl_sigwaitinfo,pcntl_sigtimedwait,pcntl_exec,pcntl_getpriority,pcntl_setpriority,pcntl_async_signals,pcntl_unshare, Directory :  /usr/local/lib/python3.6/dist-packages/sympy/combinatorics/tests/

Upload File : current_dir [ Writeable ] document_root [ Writeable ]

from sympy.combinatorics.subsets import Subset, ksubsets
from sympy.testing.pytest import raises


def test_subset():
    a = Subset(['c', 'd'], ['a', 'b', 'c', 'd'])
    assert a.next_binary() == Subset(['b'], ['a', 'b', 'c', 'd'])
    assert a.prev_binary() == Subset(['c'], ['a', 'b', 'c', 'd'])
    assert a.next_lexicographic() == Subset(['d'], ['a', 'b', 'c', 'd'])
    assert a.prev_lexicographic() == Subset(['c'], ['a', 'b', 'c', 'd'])
    assert a.next_gray() == Subset(['c'], ['a', 'b', 'c', 'd'])
    assert a.prev_gray() == Subset(['d'], ['a', 'b', 'c', 'd'])
    assert a.rank_binary == 3
    assert a.rank_lexicographic == 14
    assert a.rank_gray == 2
    assert a.cardinality == 16
    assert a.size == 2
    assert Subset.bitlist_from_subset(a, ['a', 'b', 'c', 'd']) == '0011'

    a = Subset([2, 5, 7], [1, 2, 3, 4, 5, 6, 7])
    assert a.next_binary() == Subset([2, 5, 6], [1, 2, 3, 4, 5, 6, 7])
    assert a.prev_binary() == Subset([2, 5], [1, 2, 3, 4, 5, 6, 7])
    assert a.next_lexicographic() == Subset([2, 6], [1, 2, 3, 4, 5, 6, 7])
    assert a.prev_lexicographic() == Subset([2, 5, 6, 7], [1, 2, 3, 4, 5, 6, 7])
    assert a.next_gray() == Subset([2, 5, 6, 7], [1, 2, 3, 4, 5, 6, 7])
    assert a.prev_gray() == Subset([2, 5], [1, 2, 3, 4, 5, 6, 7])
    assert a.rank_binary == 37
    assert a.rank_lexicographic == 93
    assert a.rank_gray == 57
    assert a.cardinality == 128

    superset = ['a', 'b', 'c', 'd']
    assert Subset.unrank_binary(4, superset).rank_binary == 4
    assert Subset.unrank_gray(10, superset).rank_gray == 10

    superset = [1, 2, 3, 4, 5, 6, 7, 8, 9]
    assert Subset.unrank_binary(33, superset).rank_binary == 33
    assert Subset.unrank_gray(25, superset).rank_gray == 25

    a = Subset([], ['a', 'b', 'c', 'd'])
    i = 1
    while a.subset != Subset(['d'], ['a', 'b', 'c', 'd']).subset:
        a = a.next_lexicographic()
        i = i + 1
    assert i == 16

    i = 1
    while a.subset != Subset([], ['a', 'b', 'c', 'd']).subset:
        a = a.prev_lexicographic()
        i = i + 1
    assert i == 16

    raises(ValueError, lambda: Subset(['a', 'b'], ['a']))
    raises(ValueError, lambda: Subset(['a'], ['b', 'c']))
    raises(ValueError, lambda: Subset.subset_from_bitlist(['a', 'b'], '010'))


def test_ksubsets():
    assert list(ksubsets([1, 2, 3], 2)) == [(1, 2), (1, 3), (2, 3)]
    assert list(ksubsets([1, 2, 3, 4, 5], 2)) == [(1, 2), (1, 3), (1, 4),
               (1, 5), (2, 3), (2, 4), (2, 5), (3, 4), (3, 5), (4, 5)]