39 lines
417 B
Ruby
39 lines
417 B
Ruby
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limit=2000000;
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crosslimit=Math.sqrt(2000000);
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sieve=[0]*limit;
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i=0;
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while i<limit
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sieve[i]=false
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i+=1
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end
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i=4
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while i<limit
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sieve[i]=1;
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i+=2
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end
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i=3
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while i<crosslimit
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if !sieve[i]
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m=i*i
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while m<limit
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sieve[m]=true;
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m+=2*i
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end
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end
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i+=2
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end
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sum=0;
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i=2;
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while i<limit
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if not sieve[i]
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sum += i
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end
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i+=1
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end
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puts sum
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