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:: euclid-basic.py
#!/usr/local/bin/python3
import sys


def euclid(m, n) :
    if n==0 : return m
    return euclid(n, m % n)


m = int(sys.argv[1])
n = int(sys.argv[2])
print(euclid(m, n))
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:: euclid-brute.py
#!/usr/local/bin/python3
import sys

def euclid(m, n) :
    for i in range(min(m, n), 0, -1) : 
        if m%i==0 and n%i==0 : return i


m = int(sys.argv[1])
n = int(sys.argv[2])
print(euclid(m, n))
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:: euclid-m-fail.py
#!/usr/local/bin/python3
import sys

def euclid(m, n) :
    if m%n==0 : return n
    return euclid(m, m % n)


m = int(sys.argv[1])
n = int(sys.argv[2])
print(euclid(m, n))
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:: euclid-m-minus-noswap-fail.py
#!/usr/local/bin/python3
import sys

# use m which is larger -> infinite loop
def euclid(m, n) :
    print(m, n)
    if n==0 : 
        print()
        return m
    return euclid(m, m - n)

m = int(sys.argv[1])
n = int(sys.argv[2])
print(euclid(m, n))
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:: euclid-min.py
#!/usr/local/bin/python3
import sys

def euclid(m, n) :
    if n==0 : return m
    return euclid(n, min(m % n, n - m%n))


m = int(sys.argv[1])
n = int(sys.argv[2])
print(euclid(m, n))
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:: euclid-minus-noswap-fail.py
#!/usr/local/bin/python3
import sys

# use m which is larger -> infinite loop
def euclid(m, n) :
    print(m, n)
    if n==0 : 
        print()
        return m
    return euclid(n, m - n)

m = int(sys.argv[1])
n = int(sys.argv[2])
print(euclid(m, n))
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:: euclid-minus-swap.py
#!/usr/local/bin/python3
import sys

# use gcd(m, n) = gcd(n, m-n) = 
def euclid(m, n) :
    if m<n : (m, n) = (n, m)
    # assert m >= n
    if n==0 : return m
    return euclid(n, m - n)


m = int(sys.argv[1])
n = int(sys.argv[2])
print(euclid(m, n))
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:: euclid-norecurse.py
#!/usr/local/bin/python3
import sys


def euclid(m, n) :
    while n!=0 :
        tmp = m % n
        m = n
        n = tmp
    return m

m = int(sys.argv[1])
n = int(sys.argv[2])
print(euclid(m, n))
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:: euclid-norecurse2.py
#!/usr/local/bin/python3
import sys

# this code avoids swapping
def euclid(m, n) :
    while n!=0 :
        m = m % n
        if m==0 : return n
        n = n % m

    return m

m = int(sys.argv[1])
n = int(sys.argv[2])
print(euclid(m, n))
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:: euclid-norecurse3.py
#!/usr/local/bin/python3
import sys


# this code uses Python's structural assignment feature
def euclid(m, n) :
    while n!=0 :
        (m, n) = (n, m%n)
    return m

m = int(sys.argv[1])
n = int(sys.argv[2])
print(euclid(m, n))