mirror of
https://github.com/TheAlgorithms/C
synced 2024-11-26 07:19:55 +03:00
37 lines
623 B
C
37 lines
623 B
C
#include <stdio.h>
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#include <math.h>
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#include <stdlib.h>
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char is_prime(long n)
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{
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for (long i = 2; i < sqrtl(n) + 1; i++)
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if ( n % i == 0)
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return 0;
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return 1;
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}
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long long sum_of_primes(long N)
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{
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long long sum = 2;
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for (long i = 3; i < N; i+=2) /* skip even numbers */
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if (is_prime(i))
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sum += i;
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return sum;
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}
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int main(int argc, char* argv[])
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{
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long n = 100;
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if (argc == 2) /* if command line argument is provided */
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n = atol(argv[1]); /* use that as the upper limit */
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printf("%ld: %lld\n", n, sum_of_primes(n));
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return 0;
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} |