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paulhankin/prime_pairs.py

Created December 31, 2016 18:42
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prime_pairs.py
def primes(n):
x = [False] * (n + 1)
for i in xrange(2, n + 1):
if x[i]: continue
yield i
for j in xrange(2 * i, n + 1, i):
x[j] = True
def prime_pairs(n):
ps = list(primes(n))
i, j = 0, len(ps) - 1
while i <= j:
while i <= j and ps[i] + ps[j] > n:
j -= 1
if i <= j and ps[i] + ps[j] == n:
yield ps[i], ps[j]
i += 1
print list(prime_pairs(10))
print list(prime_pairs(100))
print list(prime_pairs(100000))
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