Timus online judge 1086 Cryptography

A solution in c++

#include<bits/stdc++.h>

using namespace std;

/// Typedef
typedef long long int ll;

#define FastIO  ios_base::sync_with_stdio(false); cin.tie(0);
#define sc1(a) scanf("%lld",&a)
#define sc2(a,b) scanf("%lld %lld",&a,&b)
#define sc3(a,b,c) scanf("%lld %lld %lld",&a,&b,&c)

#define pf1(a) printf("%lld\n",a)
#define pf2(a,b) printf("%lld %lld\n",a,b)
#define pf3(a,b,c) printf("%lld %lld %lld\n",a,b,c)

#define fr1(n) for(i=0;i<n;i++)
#define fr2(n) for(i=1;i<n;i++)
#define fr3(i,a,b) for(i=a;i<=b;i++)

/*primes in range 1 - n
1 - 100(1e2) -> 25 primes
1 - 1000(1e3) -> 168 primes
1 - 10000(1e4) -> 1229 primes
1 - 100000(1e5) -> 9592 primes
1 - 1000000(1e6) -> 78498 primes
1 - 10000000(1e7) -> 664579 primes
large primes ->
104729 1299709 15485863 179424673 2147483647 32416190071 112272535095293 48112959837082048697
*/

#define mx 1000005
#define mod 1000000007

vector<ll>vc;
vector<pair<ll, ll> >vcp,vcp2,vcx,vcy;
map<ll, ll>mp,mp2;
map<ll, ll>::iterator it,it2;
set<string>my1;

ll checkprime[mx];
vector<ll>prime;

void sieve()
{
    ll n,i,j;
    for(i=4; i<mx; i+=2) checkprime[i] = 1;
    for(i=3; i*i<=mx; i+=2){
        if(checkprime[i]==0){
            for(j=i*i; j<mx; j+=(i+i))
                checkprime[j] = 1;
        }
    }
    for(i=2; i<mx; i++) if(!checkprime[i]) prime.push_back(i);
}

int main()
{
    FastIO;
    sieve();
    ll n,m,i,j,k,ck=0,dk=0,a,b;

    sc1(n);
    while(n--){
        sc1(a);
        pf1(prime[a-1]);
    }

}