50 lines
1.0 KiB
Python
50 lines
1.0 KiB
Python
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#!/usr/bin/env python3
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def divisors(divs):
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r = []
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for p in divs:
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r += [p*d for d in r] + [p]
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return r
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def add_divisors(n, st=2):
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for i in range(st*n, len(sieve), st*n):
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sieve[i].append(n)
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pw = 2
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while n**pw < len(sieve):
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m = n**pw
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for i in range(st*m, len(sieve), st*m):
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sieve[i][-1] *= n
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pw += 1
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target = 25
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count = 0
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s = 0
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lim = 10**5
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sieve = [x for i in range(lim//2) for x in ([], True)]
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add_divisors(2, st=1)
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for p in range(3, len(sieve)):
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if not p%2 and not sieve[p+1]:
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for d in divisors(sieve[p]):
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if pow(10, d, 9*p+9) == 1:
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break
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else:
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continue
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count += 1
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s += p + 1
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#print(count, p+1)
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if count >= target:
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break
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if not p%2 or not sieve[p]:
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continue
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for i in range(p**2, len(sieve), 2*p):
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sieve[i] = False
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add_divisors(p)
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if count < target:
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print("Limit reached. Count = {}/{}".format(count,target))
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print(s)
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