from sympy import Sieve, binomial_coefficients, binomial_coefficients_list, \
        multinomial_coefficients, Mul, S, Pow, sieve
from sympy import factorial as fac

from sympy.ntheory import isprime, n_order, is_primitive_root, \
    is_quad_residue, legendre_symbol, jacobi_symbol, npartitions, totient, \
    factorint, primefactors, divisors, randprime, nextprime, prevprime, \
    primerange, primepi, prime, pollard_rho, perfect_power, multiplicity, \
    trailing, divisor_count, primorial, pollard_pm1
from sympy.ntheory.factor_ import smoothness, smoothness_p
from sympy.ntheory.generate import cycle_length
from sympy.ntheory.primetest import _mr_safe_helper, mr
from sympy.ntheory.bbp_pi import pi_hex_digits
from sympy.ntheory.modular import crt, crt1, crt2, solve_congruence

from sympy.utilities.pytest import raises
from sympy.utilities.iterables import capture
from sympy.ntheory.multinomial import multinomial_coefficients_iterator

def test_trailing():
    assert trailing(0) == 0
    assert trailing(1) == 0
    assert trailing(-1) == 0
    assert trailing(2) == 1
    assert trailing(7) == 0
    assert trailing(-7) == 0
    for i in range(100):
        assert trailing((1<<i)) == i
        assert trailing((1<<i) * 31337) == i
    assert trailing((1<<1000001)) == 1000001
    assert trailing((1<<273956)*7**37) == 273956

def test_multiplicity():
    for b in range(2, 20):
        for i in range(100):
            assert multiplicity(b, b**i) == i
            assert multiplicity(b, (b**i) * 23) == i
            assert multiplicity(b, (b**i) * 1000249) == i
    # Should be fast
    assert multiplicity(10, 10**10023) == 10023
    # Should exit quickly
    assert multiplicity(10**10, 10**10) == 1
    # Should raise errors for bad input
    raises(ValueError, lambda: multiplicity(1, 1))
    raises(ValueError, lambda: multiplicity(1, 2))
    raises(ValueError, lambda: multiplicity(1.3, 2))

def test_perfect_power():
    assert perfect_power(0) is False
    assert perfect_power(1) is False
    assert perfect_power(2) is False
    assert perfect_power(3) is False
    assert perfect_power(4) == (2, 2)
    assert perfect_power(14) is False
    assert perfect_power(25) == (5, 2)
    assert perfect_power(22) is False
    assert perfect_power(22, [2]) is False
    assert perfect_power(137**(3*5*13)) == (137, 3*5*13)
    assert perfect_power(137**(3*5*13) + 1) is False
    assert perfect_power(137**(3*5*13) - 1) is False
    assert perfect_power(103005006004**7) == (103005006004, 7)
    assert perfect_power(103005006004**7+1) is False
    assert perfect_power(103005006004**7-1) is False
    assert perfect_power(103005006004**12) == (103005006004, 12)
    assert perfect_power(103005006004**12+1) is False
    assert perfect_power(103005006004**12-1) is False
    assert perfect_power(2**10007) == (2, 10007)
    assert perfect_power(2**10007+1) is False
    assert perfect_power(2**10007-1) is False
    assert perfect_power((9**99 + 1)**60) == (9**99 + 1, 60)
    assert perfect_power((9**99 + 1)**60+1) is False
    assert perfect_power((9**99 + 1)**60-1) is False
    assert perfect_power((10**40000)**2, big=False) == (10**40000, 2)
    assert perfect_power(10**100000) == (10, 100000)
    assert perfect_power(10**100001) == (10, 100001)
    assert perfect_power(13**4, [3, 5]) is False
    assert perfect_power(3**4, [3, 10], factor=0) is False
    assert perfect_power(3**3*5**3) == (15, 3)
    assert perfect_power(2**3*5**5) is False
    assert perfect_power(2*13**4) is False
    assert perfect_power(2**5*3**3) is False

def test_isprime():
    s = Sieve()
    s.extend(100000)
    ps = set(s.primerange(2, 100001))
    for n in range(100001):
        # if (n in ps) != isprime(n): print n
        assert (n in ps) == isprime(n)
    assert isprime(179424673)
    # Some Mersenne primes
    assert isprime(2**61 - 1)
    assert isprime(2**89 - 1)
    assert isprime(2**607 - 1)
    assert not isprime(2**601 - 1)
    #Arnault's number
    assert isprime(int('''
803837457453639491257079614341942108138837688287558145837488917522297\
427376533365218650233616396004545791504202360320876656996676098728404\
396540823292873879185086916685732826776177102938969773947016708230428\
687109997439976544144845341155872450633409279022275296229414984230688\
1685404326457534018329786111298960644845216191652872597534901'''))
    # pseudoprime that passes the base set [2, 3, 7, 61, 24251]
    assert not isprime(9188353522314541)

    assert _mr_safe_helper(
        "if n < 170584961: return mr(n, [350, 3958281543])") == \
     ' # [350, 3958281543] stot = 1 clear [2, 3, 5, 7, 29, 67, 679067]'
    assert _mr_safe_helper(
        "if n < 3474749660383: return mr(n, [2, 3, 5, 7, 11, 13])") == \
        ' # [2, 3, 5, 7, 11, 13] stot = 7 clear == bases'

def test_prime():
    assert prime(1) == 2
    assert prime(2) == 3
    assert prime(5) == 11
    assert prime(11) == 31
    assert prime(57) == 269
    assert prime(296) == 1949
    assert prime(559) == 4051
    assert prime(3000) == 27449
    assert prime(4096) == 38873
    assert prime(9096) == 94321
    assert prime(25023) == 287341
    raises(ValueError, lambda: prime(0))

def test_primepi():
    assert primepi(1) == 0
    assert primepi(2) == 1
    assert primepi(5) == 3
    assert primepi(11) == 5
    assert primepi(57) == 16
    assert primepi(296) == 62
    assert primepi(559) == 102
    assert primepi(3000) == 430
    assert primepi(4096) == 564
    assert primepi(9096) == 1128
    assert primepi(25023) == 2763

def test_generate():
    assert nextprime(-4) == 2
    assert nextprime(2) == 3
    assert nextprime(5) == 7
    assert nextprime(12) == 13
    assert nextprime(90) == 97
    assert nextprime(10**40) == (10**40 + 121)
    assert prevprime(3) == 2
    assert prevprime(7) == 5
    assert prevprime(13) == 11
    assert prevprime(97) == 89
    assert prevprime(10**40) == (10**40 - 17)
    assert list(primerange(2, 7)) == [2, 3, 5]
    assert list(primerange(2, 10)) == [2, 3, 5, 7]
    assert list(primerange(1050, 1100)) == [1051, 1061, \
        1063, 1069, 1087, 1091, 1093, 1097]
    s = Sieve()
    for i in range(30, 2350, 376):
        for j in range(2, 5096, 1139):
            A = list(s.primerange(i, i+j))
            B = list(primerange(i, i+j))
            assert A == B
    s = Sieve()
    assert s[10] == 29

    assert nextprime(2, 2) == 5

    raises(ValueError, lambda: totient(0))

    raises(ValueError, lambda: primorial(0))

    assert mr(1, [2]) == False

    func = lambda i: (i**2 + 1) % 51
    assert cycle_length(func, 4).next() == (6, 2)
    assert list(cycle_length(func, 4, values=True)) == \
           [17, 35, 2, 5, 26, 14, 44, 50, 2, 5, 26, 14]
    assert cycle_length(func, 4, nmax=5).next() == (5, None)
    assert list(cycle_length(func, 4, nmax=5, values=True)) == \
           [17, 35, 2, 5, 26]

def test_randprime():
    import random
    random.seed(1234)
    assert randprime(2, 3) == 2
    assert randprime(1, 3) == 2
    assert randprime(3, 5) == 3
    raises(ValueError, lambda: randprime(20, 22))
    for a in [100, 300, 500, 250000]:
        for b in [100, 300, 500, 250000]:
            p = randprime(a, a+b)
            assert a <= p < (a+b) and isprime(p)

def fac_multiplicity(n, p):
    """Return the power of the prime number p in the
    factorization of n!"""
    if p > n: return 0
    if p > n//2: return 1
    q, m = n, 0
    while q >= p:
        q //= p
        m += q
    return m

def multiproduct(seq=(), start=1):
    """
    Return the product of a sequence of factors with multiplicities,
    times the value of the parameter ``start``. The input may be a
    sequence of (factor, exponent) pairs or a dict of such pairs.

        >>> multiproduct({3:7, 2:5}, 4) # = 3**7 * 2**5 * 4
        279936

    """
    if not seq:
        return start
    if isinstance(seq, dict):
        seq = seq.iteritems()
    units = start
    multi = []
    for base, exp in seq:
        if not exp:
            continue
        elif exp == 1:
            units *= base
        else:
            if exp % 2:
                units *= base
            multi.append((base, exp//2))
    return units * multiproduct(multi)**2

def test_factorint():
    assert primefactors(123456) == [2, 3, 643]
    assert factorint(0) == {0:1}
    assert factorint(1) == {}
    assert factorint(-1) == {-1:1}
    assert factorint(-2) == {-1:1, 2:1}
    assert factorint(-16) == {-1:1, 2:4}
    assert factorint(2) == {2:1}
    assert factorint(126) == {2:1, 3:2, 7:1}
    assert factorint(123456) == {2:6, 3:1, 643:1}
    assert factorint(5951757) == {3:1, 7:1, 29:2, 337:1}
    assert factorint(64015937) == {7993:1, 8009:1}
    assert factorint(2**(2**6) + 1) == {274177:1, 67280421310721:1}
    assert multiproduct(factorint(fac(200))) == fac(200)
    for b, e in factorint(fac(150)).items():
        assert e == fac_multiplicity(150, b)
    assert factorint(103005006059**7) == {103005006059:7}
    assert factorint(31337**191) == {31337:191}
    assert factorint(2**1000 * 3**500 * 257**127 * 383**60) == \
        {2:1000, 3:500, 257:127, 383:60}
    assert len(factorint(fac(10000))) == 1229
    assert factorint(12932983746293756928584532764589230) == \
        {2: 1, 5: 1, 73: 1, 727719592270351: 1, 63564265087747: 1, 383: 1}
    assert factorint(727719592270351) == {727719592270351:1}
    assert factorint(2**64+1, use_trial=False) == factorint(2**64+1)
    for n in range(60000):
        assert multiproduct(factorint(n)) == n
    assert pollard_rho(2**64+1, seed=1) == 274177
    assert pollard_rho(19, seed=1) is None
    assert factorint(3, limit=2) == {3: 1}
    assert factorint(12345) == {3: 1, 5: 1, 823: 1}
    assert factorint(12345, limit=3) == {4115: 1, 3: 1} # the 5 is greater than the limit
    assert factorint(1, limit=1) == {}
    assert factorint(12, limit=1) == {12: 1}
    assert factorint(30, limit=2) == {2: 1, 15: 1}
    assert factorint(16, limit=2) == {2: 4}
    assert factorint(124, limit=3) == {2: 2, 31: 1}
    assert factorint(4*31**2, limit=3) == {2: 2, 31: 2}
    p1 = nextprime(2**32)
    p2 = nextprime(2**16)
    p3 = nextprime(p2)
    assert factorint(p1*p2*p3) == {p1: 1, p2: 1, p3: 1}
    assert factorint(13*17*19, limit=15) == {13: 1, 17*19: 1}
    assert factorint(1951*15013*15053, limit=2000) == {225990689: 1, 1951: 1}
    assert factorint(primorial(17)+1, use_pm1=0) == \
           {19026377261L: 1, 3467: 1, 277: 1, 105229: 1}
    # when prime b is closer than approx sqrt(8*p) to prime p then they are
    # "close" and have a trivial factorization
    a=nextprime(2**2**8) # 78 digits
    b=nextprime(a + 2**2**4)
    assert 'Fermat' in capture(lambda: factorint(a*b, verbose=1))

    raises(ValueError, lambda: pollard_rho(4))
    raises(ValueError, lambda: pollard_pm1(3))
    raises(ValueError, lambda: pollard_pm1(10, B=2))
    # verbose coverage
    n = nextprime(2**16)*nextprime(2**17)*nextprime(1901)
    assert 'with primes' in capture(lambda: factorint(n, verbose=1))
    capture(lambda: factorint(nextprime(2**16)*1012, verbose=1))

    n=nextprime(2**17)
    capture(lambda: factorint(n**3, verbose=1)) # perfect power termination
    capture(lambda: factorint(2*n, verbose=1)) # factoring complete msg

    # exceed 1st
    n=nextprime(2**17)
    n*=nextprime(n)
    assert '1000' in capture(lambda: factorint(n, limit=1000, verbose=1))
    n*=nextprime(n)
    assert len(factorint(n)) == 3
    assert len(factorint(n, limit=p1)) == 3
    n*=nextprime(2*n)
    # exceed 2nd
    assert '2001' in capture(lambda: factorint(n, limit=2000, verbose=1))
    assert capture(lambda: factorint(n, limit=4000, verbose=1)).count('Pollard') == 2
    # non-prime pm1 result
    n=nextprime(8069)
    n*=nextprime(2*n)*nextprime(2*n, 2)
    capture(lambda: factorint(n, verbose=1)) # non-prime pm1 result
    # factor fermat composite
    p1 = nextprime(2**17)
    p2 = nextprime(2*p1)
    assert factorint((p1*p2**2)**3) == {p1: 3, p2: 6}

def divisors_and_divisor_count():
    assert divisors(-1) == [1]
    assert divisors(0) == []
    assert divisors(1) == [1]
    assert divisors(2) == [1, 2]
    assert divisors(3) == [1, 3]
    assert divisors(17) == [1, 17]
    assert divisors(10) == [1, 2, 5, 10]
    assert divisors(100) == [1, 2, 4, 5, 10, 20, 25, 50, 100]
    assert divisors(101) == [1, 101]

    assert divisor_count(0) == 0
    assert divisor_count(-1) == 1
    assert divisor_count(1) == 1
    assert divisor_count(6) == 4
    assert divisor_count(12) == 6

    assert divisor_count(180, 3) == divisor_count(180//3)
    assert divisor_count(2*3*5, 7) == 0

def test_totient():
    assert [totient(k) for k in range(1, 12)] == \
        [1, 1, 2, 2, 4, 2, 6, 4, 6, 4, 10]
    assert totient(5005) == 2880
    assert totient(5006) == 2502
    assert totient(5009) == 5008

def test_partitions():
    assert [npartitions(k) for k in range(13)] == \
        [1, 1, 2, 3, 5, 7, 11, 15, 22, 30, 42, 56, 77]
    assert npartitions(100) == 190569292
    assert npartitions(200) == 3972999029388
    assert npartitions(1000) == 24061467864032622473692149727991
    assert npartitions(2000) == 4720819175619413888601432406799959512200344166
    assert npartitions(10000) % 10**10 == 6916435144
    assert npartitions(100000) % 10**10 == 9421098519

def test_residue():
    assert n_order(2, 13) == 12
    assert [n_order(a, 7) for a in range(1, 7)] == \
           [1, 3, 6, 3, 6, 2]
    assert n_order(5, 17) == 16
    assert n_order(17, 11) == n_order(6, 11)
    assert n_order(101, 119) == 6

    assert is_primitive_root(2, 7) == False
    assert is_primitive_root(3, 8) == False
    assert is_primitive_root(11, 14) == False
    assert is_primitive_root(12, 17) == is_primitive_root(29, 17)

    assert is_quad_residue(3, 7) == False
    assert is_quad_residue(10, 13) == True
    assert is_quad_residue(12364, 139) == is_quad_residue(12364 % 139, 139)
    assert is_quad_residue(207, 251) == True
    assert is_quad_residue(0, 1) == True
    assert is_quad_residue(1, 1) == True
    assert is_quad_residue(0, 2) == is_quad_residue(1, 2) == True
    assert is_quad_residue(1, 4) == True
    assert is_quad_residue(2, 27) == False
    assert [j for j in range(14) if is_quad_residue(j, 14)] == \
           [0, 1, 2, 4, 7, 8, 9, 11]
    raises(ValueError, lambda: is_quad_residue(1.1, 2))

    assert legendre_symbol(5, 11) == 1
    assert legendre_symbol(25, 41) == 1
    assert legendre_symbol(67, 101) == -1
    assert legendre_symbol(0, 13) == 0
    assert legendre_symbol(9, 3) == 0
    raises(ValueError, lambda: legendre_symbol(2, 4))

    assert jacobi_symbol(25, 41) == 1
    assert jacobi_symbol(-23, 83) == -1
    assert jacobi_symbol(3, 9) == 0
    assert jacobi_symbol(42, 97) == -1
    assert jacobi_symbol(3, 5) == -1
    assert jacobi_symbol(7, 9) == 1
    assert jacobi_symbol(0, 3) == 0
    assert jacobi_symbol(0, 1) == 1
    assert jacobi_symbol(2, 1) == 1
    assert jacobi_symbol(1, 3) == 1
    raises(ValueError, lambda: jacobi_symbol(3, 8))

def test_hex_pi_nth_digits():
    assert pi_hex_digits(0) == '3243f6a8885a30'
    assert pi_hex_digits(1) == '243f6a8885a308'
    assert pi_hex_digits(10000) == '68ac8fcfb8016c'

def test_crt():
    def mcrt(m, v, r, symmetric=False):
        assert crt(m, v, symmetric)[0] == r
        mm, e, s = crt1(m)
        assert crt2(m, v, mm, e, s, symmetric) == (r, mm)

    mcrt([2, 3, 5], [0, 0, 0], 0)
    mcrt([2, 3, 5], [1, 1, 1], 1)

    mcrt([2, 3, 5], [-1, -1, -1], -1, True)
    mcrt([2, 3, 5], [-1, -1, -1], 2*3*5 - 1, False)

    assert crt([656, 350], [811, 133], symmetric=True) == (-56917, 114800)

def test_binomial_coefficients_list():
    assert binomial_coefficients_list(0) == [1]
    assert binomial_coefficients_list(1) == [1, 1]
    assert binomial_coefficients_list(2) == [1, 2, 1]
    assert binomial_coefficients_list(3) == [1, 3, 3, 1]
    assert binomial_coefficients_list(4) == [1, 4, 6, 4, 1]
    assert binomial_coefficients_list(5) == [1, 5, 10, 10, 5, 1]
    assert binomial_coefficients_list(6) == [1, 6, 15, 20, 15, 6, 1]

def test_binomial_coefficients():
    for n in range(15):
        c = binomial_coefficients(n)
        l = [c[k] for k in sorted(c)]
        assert l == binomial_coefficients_list(n)

def test_multinomial_coefficients():
    assert multinomial_coefficients(1, 1) == {(1,): 1}
    assert multinomial_coefficients(1, 2) == {(2,): 1}
    assert multinomial_coefficients(1, 3) == {(3,): 1}
    assert multinomial_coefficients(2, 0) == {(0, 0): 1}
    assert multinomial_coefficients(2, 1) == {(0, 1): 1, (1, 0): 1}
    assert multinomial_coefficients(2, 2) == {(2, 0): 1, (0, 2): 1, (1, 1): 2}
    assert multinomial_coefficients(2, 3) == {(3, 0): 1, (1, 2): 3, (0, 3): 1,
            (2, 1): 3}
    assert multinomial_coefficients(3, 1) == {(1, 0, 0): 1, (0, 1, 0): 1,
            (0, 0, 1): 1}
    assert multinomial_coefficients(3, 2) == {(0, 1, 1): 2, (0, 0, 2): 1,
            (1, 1, 0): 2, (0, 2, 0): 1, (1, 0, 1): 2, (2, 0, 0): 1}
    mc = multinomial_coefficients(3, 3)
    assert mc == {(2, 1, 0): 3, (0, 3, 0): 1,
            (1, 0, 2): 3, (0, 2, 1): 3, (0, 1, 2): 3, (3, 0, 0): 1,
            (2, 0, 1): 3, (1, 2, 0): 3, (1, 1, 1): 6, (0, 0, 3): 1}
    assert dict(multinomial_coefficients_iterator(2, 0)) == {(0, 0): 1}
    assert dict(multinomial_coefficients_iterator(2, 1)) == {(0, 1): 1, (1, 0): 1}
    assert dict(multinomial_coefficients_iterator(2, 2)) == \
        {(2, 0): 1, (0, 2): 1, (1, 1): 2}
    assert dict(multinomial_coefficients_iterator(3, 3)) == mc
    it = multinomial_coefficients_iterator(7, 2)
    assert [it.next() for i in range(4)] == \
    [((2, 0, 0, 0, 0, 0, 0), 1), ((1, 1, 0, 0, 0, 0, 0), 2),
      ((0, 2, 0, 0, 0, 0, 0), 1), ((1, 0, 1, 0, 0, 0, 0), 2)]

def test_issue1257():
    assert factorint(1030903) == {53: 2, 367: 1}

def test_divisors():
    assert divisors(28) == [1, 2, 4, 7, 14, 28]
    assert [x for x in divisors(3*5*7, 1)] == [1, 3, 5, 15, 7, 21, 35, 105]
    assert divisors(0) == []

def test_divisor_count():
    assert divisor_count(0) == 0
    assert divisor_count(6) == 4

def test_primorial():
    assert primorial(1) == 2
    assert primorial(1, nth=0) == 1
    assert primorial(2) == 6
    assert primorial(2, nth=0) == 2
    assert primorial(4, nth=0) == 6

def test_smoothness_and_smoothness_p():
    assert smoothness(1) == (1, 1)
    assert smoothness(2**4*3**2) == (3, 16)

    assert smoothness_p(10431, m=1) == \
        (1, [(3, (2, 2, 4)), (19, (1, 5, 5)), (61, (1, 31, 31))])
    assert smoothness_p(10431) == \
        (-1, [(3, (2, 2, 2)), (19, (1, 3, 9)), (61, (1, 5, 5))])
    assert smoothness_p(10431, power=1) == \
        (-1, [(3, (2, 2, 2)), (61, (1, 5, 5)), (19, (1, 3, 9))])
    assert smoothness_p(21477639576571, visual=1) == \
        'p**i=4410317**1 has p-1 B=1787, B-pow=1787\n' + \
        'p**i=4869863**1 has p-1 B=2434931, B-pow=2434931'

def test_visual_factorint():
    assert factorint(1, visual=1) == 1
    forty2 = factorint(42, visual=True)
    assert type(forty2) == Mul
    assert str(forty2) == '2**1*3**1*7**1'
    assert factorint(1, visual=True) is S.One
    no = dict(evaluate=False)
    assert factorint(42**2, visual=True) == Mul(Pow(2, 2, **no),
                                                Pow(3, 2, **no),
                                                Pow(7, 2, **no), **no)
    assert -1 in factorint(-42, visual=True).args

def test_visual_io():
    sm = smoothness_p
    fi = factorint
    # with smoothness_p
    n = 124
    d = fi(n)
    m = fi(d, visual=True)
    t = sm(n)
    s = sm(t)
    for th in [d, s, t, n, m]:
        assert sm(th, visual=True) == s
        assert sm(th, visual=1) == s
    for th in [d, s, t, n, m]:
        assert sm(th, visual=False) == t
    assert [sm(th, visual=None) for th in [d, s, t, n, m]] == [s, d, s, t, t]
    assert [sm(th, visual=0) for th in [d, s, t, n, m]] == [s, d, s, t, t]

    # with factorint
    for th in [d, m, n]:
        assert fi(th, visual=True) == m
        assert fi(th, visual=1) == m
    for th in [d, m, n]:
        assert fi(th, visual=False) == d
    assert [fi(th, visual=None) for th in [d, m, n]] == [m, d, d]
    assert [fi(th, visual=0) for th in [d, m, n]] == [m, d, d]

    # test reevaluation
    no = dict(evaluate=False)
    assert sm({4: 2}, visual=False) == sm(16)
    assert sm(Mul(*[Pow(k, v, **no) for k, v in {4: 2, 2: 6}.items()], **no),
              visual=False) == sm(2**10)

    assert fi({4: 2}, visual=False) == fi(16)
    assert fi(Mul(*[Pow(k, v, **no) for k, v in {4: 2, 2: 6}.items()], **no),
              visual=False) == fi(2**10)

def test_modular():
    assert solve_congruence(*zip([3, 4, 2], [12, 35, 17])) == (1719, 7140)
    assert solve_congruence(*zip([3, 4, 2], [12, 6, 17])) is None
    assert solve_congruence(*zip([3, 4, 2], [13, 7, 17])) == (172, 1547)
    assert solve_congruence(*zip([-10, -3, -15], [13, 7, 17])) == (172, 1547)
    assert solve_congruence(*zip([-10, -3, 1, -15], [13, 7, 7, 17])) is None
    assert solve_congruence(*zip([-10, -5, 2, -15], [13, 7, 7, 17])) == (835, 1547)
    assert solve_congruence(*zip([-10, -5, 2, -15], [13, 7, 14, 17])) == (2382, 3094)
    assert solve_congruence(*zip([-10, 2, 2, -15], [13, 7, 14, 17])) == (2382, 3094)
    assert solve_congruence(*zip((1, 1, 2),(3, 2, 4))) is None
    raises(ValueError, lambda: solve_congruence(*zip([3, 4, 2], [12.1, 35, 17])))

def test_search():
    assert 2 in sieve
    assert 2.1 not in sieve
    assert 1 not in sieve
    assert 2**1000 not in sieve
    raises(ValueError, lambda: sieve.search(1))
