#!/usr/bin/env python3

from collections import deque
from numpy import zeros


def fetch_x(
    seed = deque([1,1,1], maxlen=3),
    a_1 = 0, a_2 = 63308, a_3 = -183326, m_1 = 2**31 - 1
):
    """
        x_n = (a_1 x_{n-1} + a_2 x_{n-2} + a_3 x_{n-3})
        with coefficients a_1 = 0, a_2 = 63308, a_3 = -183326,
        and moduli m_1 = 2**31-1 = 2147483647
        This function will remember the values of 3 previous calls
        We need to remember 3 last entries, add new ones and discard old,
        so let's use the seed deque.
    """
    def xguts():
        nonlocal seed, a_1, a_2, a_3, m_1
        literal_guts = (a_1 * seed[0] + a_2 * seed[1] + a_3 * seed[2]) % m_1
        seed.appendleft(literal_guts)       # add a new value for seed
                                            # and discard the oldest one
        return literal_guts
    return xguts

def fetch_y(
    seed = deque([1,1,1], maxlen=3),
    b_1 = 86098, b_2 = 0, b_3 = -539608, m_2 = 2145483479
):
    """
        y_n = (b_1 y_{n-1} + b_2 y_{n-2} + b_3 y_{n-3}) mod m_2
        with coefficients b_1 = 86098, b_2 = 0, b_3 = -539608,
        and moduli m_2 = 2145483479. This function will remember the values
        of 3 previous calls in the seed deque
    """
    def yguts():
        nonlocal seed, b_1, b_2, b_3, m_2
        literal_guts = (b_1 * seed[0] + b_2 * seed[1] + b_3 * seed[2]) % m_2
        seed.appendleft(literal_guts)
        return literal_guts
    return yguts

def french_rng(x, y):
    """ This is a combined multiple recursive generator by L’Ecuyer.
        Its sequence is,
        z_n = (x_n - y_n) mod m_1
        P. L’Ecuyer, “Combined Multiple Recursive Random Number Generators”,
        Operations Research, 44, 5 (1996), 816–822.
    """
    m_1 = 2**31 - 1
    def yet_another_gut():
        nonlocal x, y, m_1
        return (x() - y()) % m_1
    return yet_another_gut


N = 6

arr = zeros(N, dtype=int)       # prepare the space filled with zeros

rand = french_rng(x = fetch_x(deque([2,2,2], maxlen=3)), y = fetch_y())


for i in range (N):
    arr[i] = rand()

print (arr)