28 lines
451 B
C
28 lines
451 B
C
#include <stdio.h>
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#include <math.h>
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#define idx(n) (n - 1) / 2 - 1
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long primes[1000000];
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int main()
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{
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long i, j;
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char pdict[500001] = {[0 ... 500000] = 1};
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for (i = 3; i < 1000; i += 2)
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if (pdict[idx(i)])
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for (j = i * i; j < 1000000; j += i * 2)
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pdict[idx(j)] = 0;
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primes[0] = 2;
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j = 0;
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for (i = 3; i < 1000000; i += 2)
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if (pdict[idx(i)])
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primes[++j] = i;
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printf("%ld ", primes[78497]);
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printf("\n%ld\n", j);
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return 0;
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}
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