problem8_poly

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

unsigned int f(int n)
{
  unsigned int ans = 0, factors;
  int tmp;
  for (int x = 0; x < n; x++)
  {
    tmp = x;
    factors = 0;
    if (tmp == 1)
      factors++;
    for (int i = 2; i <= sqrt(tmp); i++)
    {
      while (tmp % i == 0)
      {
        factors++;
        tmp /= i;
        if (factors > 2)
          break;
      }
    }
    if (tmp != 1)
      factors++;

    if (factors == 2)
      ans++;
  }
  return ans;
}

int main()
{
  printf("%d\n", f(30));
  return 0;
}