uva 11105 semi-prime H-numbers

#include 
using namespace std;
const int maxn = 1000010;
bool nhp[maxn];
int hp[maxn],hpnum;
int cnt[maxn];
void pre() {
    for(int i = 5; i < 1010; i += 4)
        if(!nhp[i])
            for(int j = i * i; j < maxn; j += i)
                nhp[j] = true;
    for(int i = 5; i < maxn; i+=4)
        if(!nhp[i]) hp[hpnum++] = i;
    for(int i = 0; i < hpnum; ++i)
        for(int j = 0; j < hpnum && hp[i] * hp[j] < maxn; ++j)
            cnt[hp[i]*hp[j]] = 1;
    for(int i = 1; i < maxn; ++i) cnt[i] += cnt[i - 1];
}
int main() {
    pre();
    int n;
    while(~scanf("%d", &n) && n)
        printf("%d %d\n", n, cnt[n]);
    return 0;
}