Problem p02541 (python)

Fixed submission:
import typing

def make_divisors(n):
    lower_divisors , upper_divisors = [], []
    i = 1
    while i*i <= n:
        if n % i == 0:
            lower_divisors.append(i)
            if i != n // i:
                upper_divisors.append(n//i)
        i += 1
    return lower_divisors + upper_divisors[::-1]
  
# https://github.com/not522/ac-library-python/blob/master/atcoder/math.py
def crt(r: typing.List[int], m: typing.List[int]) -> typing.Tuple[int, int]:
    assert len(r) == len(m)

    n = len(r)

    # Contracts: 0 <= r0 < m0
    r0 = 0
    m0 = 1
    for i in range(n):
        assert 1 <= m[i]
        r1 = r[i] % m[i]
        m1 = m[i]
        if m0 < m1:
            r0, r1 = r1, r0
            m0, m1 = m1, m0
        if m0 % m1 == 0:
            if r0 % m1 != r1:
                return (0, 0)
            continue

        # assume: m0 > m1, lcm(m0, m1) >= 2 * max(m0, m1)

        '''
        (r0, m0), (r1, m1) -> (r2, m2 = lcm(m0, m1));
        r2 % m0 = r0
        r2 % m1 = r1
        -> (r0 + x*m0) % m1 = r1
        -> x*u0*g % (u1*g) = (r1 - r0) (u0*g = m0, u1*g = m1)
        -> x = (r1 - r0) / g * inv(u0) (mod u1)
        '''

        # im = inv(u0) (mod u1) (0 <= im < u1)
        g, im = _inv_gcd(m0, m1)

        u1 = m1 // g
        # |r1 - r0| < (m0 + m1) <= lcm(m0, m1)
        if (r1 - r0) % g:
            return (0, 0)

        # u1 * u1 <= m1 * m1 / g / g <= m0 * m1 / g = lcm(m0, m1)
        x = (r1 - r0) // g % u1 * im % u1

        '''
        |r0| + |m0 * x|
        < m0 + m0 * (u1 - 1)
        = m0 + m0 * m1 / g - m0
        = lcm(m0, m1)
        '''

        r0 += x * m0
        m0 *= u1  # -> lcm(m0, m1)
        if r0 < 0:
            r0 += m0

    return (r0, m0)

def _inv_gcd(a: int, b: int) -> typing.Tuple[int, int]:
    a %= b
    if a == 0:
        return (b, 0)

    # Contracts:
    # [1] s - m0 * a = 0 (mod b)
    # [2] t - m1 * a = 0 (mod b)
    # [3] s * |m1| + t * |m0| <= b
    s = b
    t = a
    m0 = 0
    m1 = 1

    while t:
        u = s // t
        s -= t * u
        m0 -= m1 * u  # |m1 * u| <= |m1| * s <= b

        # [3]:
        # (s - t * u) * |m1| + t * |m0 - m1 * u|
        # <= s * |m1| - t * u * |m1| + t * (|m0| + |m1| * u)
        # = s * |m1| + t * |m0| <= b

        s, t = t, s
        m0, m1 = m1, m0

    # by [3]: |m0| <= b/g
    # by g != b: |m0| < b/g
    if m0 < 0:
        m0 += b // s

    return (s, m0)
  
N=int(input())
F = make_divisors(2*N)

ans = 10**20
for x in F:
  y = 2*N//x
  res,_ = crt([0,-1],[x,y])
  if res != 0:
    ans = min(ans,res)
  
print(ans)

Buggy submission (verdict: Runtime Error):
from math import prod

def factorize(n):
    out=[]
    i = 2
    while 1:
        if n%i==0:
            out.append(i)
            n //= i
        else:
            i += 1
        if n == 1:break
        if i > int(n**.5+3):
            out.append(n)
            break
    
    return out
  
N = int(input())
if N == 1:
  print(1)
  exit()
elif N == 2:
  print(3)
  exit()
f = factorize(N)
if set(f)=={2}:
  f_ = prod(f)
else:
  f_ = f[-1]
for i in range(1,10**7):
  if (f_*i-1)*(f_*i)%(2*N)==0:
    print(f_*i-1)
    exit()
  elif (f_*i)*(f_*i+1)%(2*N)==0:
    print(f_*i)
    exit()

Buggy submission (verdict: Runtime Error):
def factorize(n):
    out=[]
    i = 2
    while 1:
        if n%i==0:
            out.append(i)
            n //= i
        else:
            i += 1
        if n == 1:break
        if i > int(n**.5+3):
            out.append(n)
            break
    
    return out
  
N = int(input())
f = factorize(N)[-1]
for i in range(1,10**7):
  if (f*i)*(f*i+1)%(2*N)==0:
    print(f*i)
    exit()