扩展的欧几里得算法Python实现

def extendGcd(m,b):
    if b>m:
        m,b=b,m
    x1,x2,x3=1,0,m
    y1,y2,y3=0,1,b
    while True:
        if y3==0:
            return None
        if y3==1: 
            return y2%m
        Q=x3//y3
        t1,t2,t3=x1-Q*y1,x2-Q*y2,x3-Q*y3
        x1,x2,x3=y1,y2,y3
        y1,y2,y3=t1,t2,t3