Francis-Lee-Earth

def greatest_common_divisor_extended(a, b):
    '''
    擴展歐幾里得算法 (Extended Euclidean algorithm)
    '''
    if b == 0:
        return a, 1, 0

    gcd, y, x = greatest_common_divisor_extended(b, a % b)
    return gcd, x, y - (a // b) * x

Francis-Lee-Earth

def greatest_common_divisor(a, b):
    """
    除非 b == 0，否則結果將與 b 具有相同的正負號
    (因此，當 b 除以它，結果是正號)
    """
    while b > 0:
        a, b = b, a % b

    return a

Francis-Lee-Earth

import numpy as np

a = np.array([
    [1, -2, -1],
    [2, -1, 1],
    [3, -6, -5]
])

a_inv = np.linalg.inv(a)
print("A:")

Francis-Lee-Earth

import numpy as np

a = np.array([
    [5, 12],
    [15, 25]
])

b = np.array(
    [20, 10]
)