Problem p02660 (C++) — buggy submission, verdict: Runtime Error

#include <algorithm>
#include <cassert>
#include <climits>
#include <cmath>
#include <complex>
#include <cstring>
#include <functional>
#include <iostream>
#include <map>
#include <queue>
#include <random>
#include <regex>
#include <set>
#include <stack>
#include <vector>
using namespace std;

#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define repr(i, s, n) for (int i = (s); i < (int)(n); i++)
#define revrep(i, n) for (int i = (n)-1; i >= 0; i--)
#define revrepr(i, s, n) for (int i = (n)-1; i >= s; i--)
#define debug(x) cerr << #x << ": " << x << "\\n"
#define popcnt(x) __builtin_popcount(x)

const double PI = acos(-1.0);

using ll = long long;
using P = pair<int, int>;

template <class T> inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}

template <class T> istream &operator>>(istream &is, vector<T> &v) {
  for (int i = 0; i < (int)v.size(); i++)
    cin >> v.at(i);
  return is;
}

template <class T, class U> ostream &operator<<(ostream &os, pair<T, U> p) {
  cout << '(' << p.first << ", " << p.second << ')';
  return os;
}

template <class T> void print(const vector<T> &v, const string &delimiter) {
  rep(i, v.size()) cout << (0 < i ? delimiter : "") << v.at(i);
  cout << endl;
}

template <class T>
void print(const vector<vector<T>> &vv, const string &delimiter) {
  for (const auto &v : vv)
    print(v, delimiter);
}

template <typename T> map<T, int> prime_factor(T n) {
  map<T, int> res;
  for (long long i = 2; i * i <= n; i++) {
    while (n % i == 0) {
      ++res[i];
      n /= i;
    }
  }
  if (n != 1)
    res[n] = 1;
  return res;
}

int calc(int e) {
  repr(i, 1, e + 2) {
    if (e < i * (i + 1) / 2)
      return i - 1;
  }
  return -1;
}

int main() {
  ll n;
  cin >> n;
  auto ps = prime_factor(n);
  int ans = 0;
  for (auto [_, cnt] : ps) {
    ans += calc(cnt);
    // cout << cnt << " " << calc(cnt) << endl;
  }
  cout << ans << endl;
}

Error: WA

Fixed submission:

#include <algorithm>
#include <cassert>
#include <climits>
#include <cmath>
#include <complex>
#include <cstring>
#include <functional>
#include <iostream>
#include <map>
#include <queue>
#include <random>
#include <regex>
#include <set>
#include <stack>
#include <vector>
using namespace std;

#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define repr(i, s, n) for (int i = (s); i < (int)(n); i++)
#define revrep(i, n) for (int i = (n)-1; i >= 0; i--)
#define revrepr(i, s, n) for (int i = (n)-1; i >= s; i--)
#define debug(x) cerr << #x << ": " << x << "\\n"
#define popcnt(x) __builtin_popcount(x)

const double PI = acos(-1.0);

using ll = long long;
using P = pair<int, int>;

template <class T> inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}

template <class T> istream &operator>>(istream &is, vector<T> &v) {
  for (int i = 0; i < (int)v.size(); i++)
    cin >> v.at(i);
  return is;
}

template <class T, class U> ostream &operator<<(ostream &os, pair<T, U> p) {
  cout << '(' << p.first << ", " << p.second << ')';
  return os;
}

template <class T> void print(const vector<T> &v, const string &delimiter) {
  rep(i, v.size()) cout << (0 < i ? delimiter : "") << v.at(i);
  cout << endl;
}

template <class T>
void print(const vector<vector<T>> &vv, const string &delimiter) {
  for (const auto &v : vv)
    print(v, delimiter);
}

template <typename T> map<T, int> prime_factor(T n) {
  map<T, int> res;
  for (ll i = 2; i * i <= n; i++) {
    while (n % i == 0) {
      ++res[i];
      n /= i;
    }
  }
  if (n != 1)
    res[n] = 1;
  return res;
}

int main() {
  ll n;
  cin >> n;

  auto _ps = prime_factor(n);
  using pli = pair<ll, int>;
  vector<pli> ps;
  for (auto [key, value] : _ps) {
    ps.push_back(pli(value, key));
  }
  sort(ps.rbegin(), ps.rend());

  set<ll> st;
  int ans = 0;
  rep(_, 100) {
    if (ps[0].first == 0)
      break;

    ll now = ps[0].second;
    ps[0].first--;

    bool ok = true;
    while (st.count(now)) {
      sort(ps.rbegin(), ps.rend());
      if (ps[0].first == 0) {
        ok = false;
        break;
      }

      now *= ps[0].second;
      ps[0].first--;
    }

    if (ok) {
      st.insert(now);
      ans++;
    }
  }
  cout << ans << endl;
}