auxprogs/primes.c

   1
   2 #include <stdio.h>
   3 #include <math.h>
   4
   5 int isprime ( int n )
   6 {
   7    int m;
   8    int sqrt_n = sqrt(n);
   9    for (m = 2; m <= sqrt_n+1; m++)  // +1 in case of obscure rounding error
  10       if ((n % m) == 0) return 0;
  11    return 1;
  12 }
  13
  14 int main ( int argc, char** argv )
  15 {
  16    int i;
  17    for (i = 79000; i < 81000; i++)
  18      if (isprime(i)) { printf ( "%d ", i ); fflush(stdout); }
  19    return 0;
  20 }