34 lines
509 B
Python
34 lines
509 B
Python
def pick(x, lis, out, a = 0):
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if x == 0:
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out.append(a)
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return
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a *= 10
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for i in xrange(len(lis)):
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tmp = lis[:]
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tmpa = a + lis[i]
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tmp.pop(i)
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pick(x - 1, tmp, out, tmpa)
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def isprime(x):
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if x == 2:
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return True
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if x % 2 == 0:
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return False
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temp = 3
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while temp <= int(x ** 0.5) + 1:
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if x % temp == 0: return False
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else: temp += 2
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return True
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a = [1,2,3,4,5,6,7]
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tt = []
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pick(len(a), a, tt)
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tt.reverse()
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for i in tt:
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if isprime(i):
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print i
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break
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