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

#include <bits/stdc++.h>
using namespace std;

#define rep(i, n) for (int i = 0; i < n; i++)
#define Rep(i, n) for (int i = 1; i <= n; i++)
#define sz(x) int(x.size())
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
#define YesorNo(a) printf(a ? "Yes\\n" : "No\\n")
#define endl '\\n'
#define fi first
#define se second
using ll = long long;
using P = pair<int, int>;
using Pl = pair<ll, ll>;
template <class T> using V = vector<T>;
const int dx[] = {0, 1, 0, -1, 1, 1, -1, -1};
const int dy[] = {1, 0, -1, 0, 1, -1, -1, 1};
const int inf = (1 << 30) - 1;
const ll infll = (1LL << 62) - 1;
ll ceil(const ll &a, const ll &b) { return ((a) + (b)-1) / b; }
template <class T> inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
template <class T> inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}

struct Sieve { // 篩
  int n;
  vector<int> f, primes;
  Sieve(int n = 1) : n(n), f(n + 1) {
    f[0] = f[1] = -1;
    for (ll i = 2; i <= n; ++i) {
      if (f[i])
        continue;
      primes.push_back(i);
      f[i] = i;
      for (ll j = i * i; j <= n; j += i) {
        if (!f[j])
          f[j] = i;
      }
    }
  }
  bool isPrime(int x) { return f[x] == x; } // 素数判定
  vector<int> factorList(int x) {           // 素因数列挙
    vector<int> res;
    while (x != 1) {
      res.push_back(f[x]);
      x /= f[x];
    }
    return res;
  }
  vector<P> factor(int x) { // 素因数分解 int
    vector<P> res;
    for (int p : primes) {
      int y = 0;
      while (x % p == 0)
        x /= p, y++;
      if (y != 0)
        res.emplace_back(p, y);
    }
    return res;
  }
  vector<pair<ll, int>> factorll(ll x) { // 素因数分解 long long
    vector<pair<ll, int>> res;
    for (int p : primes) {
      int y = 0;
      while (x % p == 0)
        x /= p, y++;
      if (y != 0)
        res.emplace_back(p, y);
    }
    if (x != 1)
      res.emplace_back(x, 1);
    return res;
  }
};

int main() {
  ll n;
  cin >> n;
  Sieve s(2000000);
  auto fl = s.factorll(n);
  int ans = 0;
  for (auto p : fl) {
    int c = p.se;
    int b = 1;
    while (b <= c) {
      c -= b;
      b++;
      ans++;
    }
  }
  cout << ans << endl;
}

Error: 0

Fixed submission:

#include <bits/stdc++.h>
using namespace std;

#define rep(i, n) for (int i = 0; i < n; i++)
#define Rep(i, n) for (int i = 1; i <= n; i++)
#define sz(x) int(x.size())
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
#define YesorNo(a) printf(a ? "Yes\\n" : "No\\n")
#define endl '\\n'
#define fi first
#define se second
using ll = long long;
using P = pair<int, int>;
using Pl = pair<ll, ll>;
template <class T> using V = vector<T>;
const int dx[] = {0, 1, 0, -1, 1, 1, -1, -1};
const int dy[] = {1, 0, -1, 0, 1, -1, -1, 1};
const int inf = (1 << 30) - 1;
const ll infll = (1LL << 62) - 1;
ll ceil(const ll &a, const ll &b) { return ((a) + (b)-1) / b; }
template <class T> inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
template <class T> inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}

struct Sieve { // 篩
  int n;
  vector<ll> f, primes;
  Sieve(int n = 1) : n(n), f(n + 1) {
    f[0] = f[1] = -1;
    for (ll i = 2; i <= n; ++i) {
      if (f[i])
        continue;
      primes.push_back(i);
      f[i] = i;
      for (ll j = i * i; j <= n; j += i) {
        if (!f[j])
          f[j] = i;
      }
    }
  }
  bool isPrime(int x) { return f[x] == x; } // 素数判定
  vector<int> factorList(int x) {           // 素因数列挙
    vector<int> res;
    while (x != 1) {
      res.push_back(f[x]);
      x /= f[x];
    }
    return res;
  }
  vector<P> factor(int x) { // 素因数分解(ランレングス圧縮的なもの)
    vector<int> fl = factorList(x);
    if (fl.size() == 0)
      return {};
    vector<P> res(1, P(fl[0], 0));
    for (int p : fl) {
      if (res.back().first == p) {
        res.back().second++;
      } else {
        res.emplace_back(p, 1);
      }
    }
    return res;
  }
};

int main() {
  ll n;
  cin >> n;
  if (n == 1) {
    cout << 0 << endl;
    return 0;
  }
  int m = sqrt(n) + 1;
  Sieve s(m);
  s.primes.push_back(n);
  int ans = 0;
  for (int x : s.primes) {
    ll a = x;
    while (n % a == 0) {
      ans++;
      n /= a;
      a *= x;
    }
  }
  cout << ans << endl;
}