Problem p00053 (C++) — buggy submission, verdict: Memory Limit Exceeded

// clang-format off
#include <bits/stdc++.h>
#define int long long
#define main signed main()
// #define main int main()
#define loop(i, a, n) for (int i = (a); i < (n); i++)
#define rep(i, n) loop(i, 0, n)
#define all(v) (v).begin(), (v).end()
#define rall(v) (v).rbegin(), (v).rend()
#define prec(n) fixed << setprecision(n)
#define stlice(from, to) substr(from, (to) - (from) + 1)
#define pb push_back
#define mp make_pair
#define mt make_tuple
#define fi first
#define se second
using namespace std;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<double> vd;
typedef vector<char> vc;
typedef vector<bool> vb;
typedef vector<string> vs;
typedef vector<pii> vpii;
typedef vector<vi> vvi;
typedef vector<vb> vvb;
typedef vector<vpii> vvpii;
const int INF = sizeof(int) == sizeof(long long) ? 1000000000000000000LL : 1000000000;
const int MOD = 1000000007;
const double PI = acos(-1);
template<typename A, typename B> bool cmin(A &a, const B &b) { return a > b ? (a = b, true) : false; }
template<typename A, typename B> bool cmax(A &a, const B &b) { return a < b ? (a = b, true) : false; }
bool odd(const int &n) { return n & 1; }
bool even(const int &n) { return !odd(n); }
void solve();
main { solve(); return 0; }
// clang-format on

vector<int> eratosthenes(const int &n) {
  vector<int> v(n);
  v[0] = v[1] = false;
  loop(i, 2, v.size()) v[i] = true;
  for (int i = 2; i * i < n; i++) {
    if (v[i]) {
      for (int j = i * 2; j < n; j += i) {
        v[j] = false;
      }
    }
  }
  return v;
}

void solve() {
  vi v = eratosthenes(1000000);
  int n;
  while (cin >> n, n) {
    int s = 0, i = 0;
    while (n--) {
      while (!v[i])
        i++;
      s += i++;
    }
    cout << s << endl;
  }
}

Error: MLE

Fixed submission:

// clang-format off
#include <bits/stdc++.h>
#define int long long
#define main signed main()
// #define main int main()
#define loop(i, a, n) for (int i = (a); i < (n); i++)
#define rep(i, n) loop(i, 0, n)
#define all(v) (v).begin(), (v).end()
#define rall(v) (v).rbegin(), (v).rend()
#define prec(n) fixed << setprecision(n)
#define stlice(from, to) substr(from, (to) - (from) + 1)
#define pb push_back
#define mp make_pair
#define mt make_tuple
#define fi first
#define se second
using namespace std;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<double> vd;
typedef vector<char> vc;
typedef vector<bool> vb;
typedef vector<string> vs;
typedef vector<pii> vpii;
typedef vector<vi> vvi;
typedef vector<vb> vvb;
typedef vector<vpii> vvpii;
const int INF = sizeof(int) == sizeof(long long) ? 1000000000000000000LL : 1000000000;
const int MOD = 1000000007;
const double PI = acos(-1);
template<typename A, typename B> bool cmin(A &a, const B &b) { return a > b ? (a = b, true) : false; }
template<typename A, typename B> bool cmax(A &a, const B &b) { return a < b ? (a = b, true) : false; }
bool odd(const int &n) { return n & 1; }
bool even(const int &n) { return !odd(n); }
void solve();
main { solve(); return 0; }
// clang-format on

vector<int> eratosthenes(const int &n) {
  vector<int> v(n);
  v[0] = v[1] = false;
  loop(i, 2, v.size()) v[i] = true;
  for (int i = 2; i * i < n; i++) {
    if (v[i]) {
      for (int j = i * 2; j < n; j += i) {
        v[j] = false;
      }
    }
  }
  return v;
}

void solve() {
  vi v = eratosthenes(10000000);
  int n;
  while (cin >> n, n) {
    int s = 0, i = 0;
    while (n--) {
      while (!v[i])
        i++;
      s += i++;
    }
    cout << s << endl;
  }
}