2020/13.py
def extended_gcd(a, b):
    """
    I don't claim any copyright on this. I copied it from the internet somewhere.

    Extended Greatest Common Divisor Algorithm.

    Returns:
        gcd: The greatest common divisor of a and b.
        s, t: Coefficients such that s*a + t*b = gcd

    Reference:
        https://en.wikipedia.org/wiki/Extended_Euclidean_algorithm#Pseudocode
    """
    old_r, r = a, b
    old_s, s = 1, 0
    old_t, t = 0, 1
    while r:
        quotient, remainder = divmod(old_r, r)
        old_r, r = r, remainder
        old_s, s = s, old_s - quotient * s
        old_t, t = t, old_t - quotient * t

    return old_r, old_s, old_t

    I don't claim any copyright on this. I copied it from the internet somewhere.

    Extended Greatest Common Divisor Algorithm.

    Returns:
        gcd: The greatest common divisor of a and b.
        s, t: Coefficients such that s*a + t*b = gcd

    Reference:
        https://en.wikipedia.org/wiki/Extended_Euclidean_algorithm#Pseudocode
    
I don't claim any copyright on this. I copied it from the internet somewhere.
Extended Greatest Common Divisor Algorithm.
I don ' t claim any copyright on this . I copied it from the internet somewhere . Extended Greatest Common Divisor Algorithm .
def extended_gcd(a, b):
    old_r, r = a, b
    old_s, s = 1, 0
    old_t, t = 0, 1
    while r:
        quotient, remainder = divmod(old_r, r)
        old_r, r = r, remainder
        old_s, s = s, old_s - quotient * s
        old_t, t = t, old_t - quotient * t
    return old_r, old_s, old_t
def extended_gcd ( a , b ) : old_r , r = a , b old_s , s = 1 , 0 old_t , t = 0 , 1 while r : quotient , remainder = divmod ( old_r , r ) old_r , r = r , remainder old_s , s = s , old_s - quotient * s old_t , t = t , old_t - quotient * t return old_r , old_s , old_t
I don't claim any copyright on this.
I don ' t claim any copyright on this .
"""
    I don't claim any copyright on this. I copied it from the internet somewhere.

    Extended Greatest Common Divisor Algorithm.

    Returns:
        gcd: The greatest common divisor of a and b.
        s, t: Coefficients such that s*a + t*b = gcd

    Reference:
        https://en.wikipedia.org/wiki/Extended_Euclidean_algorithm#Pseudocode
    """
The greatest common divisor of a and b.
s, t: Coefficients such that s*a + t*b = gcd
The greatest common divisor of a and b . s t : Coefficients such that s * a + t * b = gcd
gcd
a
b