Problem p03050 (C++)

Buggy submission (status: Runtime Error):

/*
        @・ω・@
*/

/*****/

#include <algorithm>
#include <cmath>
#include <functional>
#include <iomanip> //cout << fixed << setprecision(桁数);
#include <iostream>
#include <map>
#include <queue>
#include <stack>
#include <stdexcept>
#include <string>
#include <vector>

// #define int long long

using namespace std;
using ll = long long;
using ld = long double;
using pll = pair<long long, long long>;
template <class T> using vec = vector<T>;

#define debug(x) (std::cerr << x)
#define debugln(x) (std::cerr << x << "\n")
#define debug_tab(n, x) (std::cerr << strMulti("\t", n) << (x) << "\n")
#define debug_cout(x) (std::cerr << #x << " : " << (x) << "\n")
#define debug_coutvec(x)                                                       \
  std::cerr << #x << " : ";                                                    \
  _debug_coutvec(x)
#define debug_tabcout(n, x)                                                    \
  (std::cerr << strMulti("\t", n) << #x << " : " << (x) << "\n")
#define debug_headcout(h, x) (std::cerr << h << " : " << (x) << "\n")
#define debug_tabheadcout(n, h, x)                                             \
  (std::cerr << strMulti("\t", n) << h << " : " << (x) << "\n")

#define rep(i, n) for (int i = 0, i##_len = (n); i < i##_len; ++i)
#define rep1(i, n) for (int i = 1, i##_len = (n); i <= i##_len; ++i)
#define rrep(i, n) for (int i = (n)-1; i >= 0; --i)
#define rrep1(i, n) for (int i = (n); i > 0; --i)
#define step(i, a, n) for (int i = (a), i##_len = (a) + (n); i < i##_len; ++i)
#define rstep(i, a, n)                                                         \
  for (int i = (a) + (n)-1, i##_len = (a); i >= i##_len; --i)
#define range(i, a, b) for (int i = (a), i##_len = (b); i < i##_len; ++i)
#define rrange(i, a, b) for (int i = (b)-1, i##_len = (a); i >= i##_len; --i)
#define repll(i, n) for (ll i = 0, i##_len = (n); i < i##_len; ++i)
#define rep1ll(i, n) for (ll i = 1, i##_len = (n); i <= i##_len; ++i)
#define rrepll(i, n) for (ll i = (n)-1; i >= 0; --i)
#define rrep1ll(i, n) for (ll i = (n); i > 0; --i)
#define stepll(i, a, n) for (ll i = (a), i##_len = (a) + (n); i < i##_len; ++i)
#define rstepll(i, a, n)                                                       \
  for (ll i = (a) + (n)-1, i##_len = (a); i >= i##_len; --i)
#define rangell(i, a, b) for (ll i = (a), i##_len = (b); i < i##_len; ++i)
#define rrangell(i, a, b) for (ll i = (b)-1, i##_len = (a); i >= i##_len; --i)
#define all(x) (x).begin(), (x).end()
#define pair(a, b) make_pair(a, b)
std::string strMulti(std::string t, int n) {
  std::string out = "";
  for (int i = 0; i < n; i++) {
    out += t;
  }
  return out;
}
template <class T> void _debug_coutvec(vector<T> ar, string space = " ") {
  rep(i, ar.size()) { debug(ar[i] << space); }
  debugln("");
}
constexpr int INF = 2000000000; // 2*10^9
constexpr ll INFL = 1ll << 60ll;

template <class T> bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
template <class T> bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
template <class T> T divup(T a, T b) {
  if (a % b == 0) {
    return a / b;
  }
  return a / b + 1;
}
template <class T> bool cmp_2nd(pair<T, T> a, pair<T, T> b) {
  if (a.second != b.second) {
    return a.second < b.second;
  }
  return a.first < b.first;
}
template <class T> T mod_pow(T x, T n, const T &p) {
  T ret = 1;
  while (n > 0) {
    if (n & 1) {
      (ret *= x) %= p;
    }
    (x *= x) %= p;
    n >>= 1;
  }
  return ret;
}
template <class T> T math_P(T m, T n) {
  T ret = 1;
  for (T i = m; i > m - n; i--) {
    ret *= i;
  }
  return ret;
}
template <class T> T math_C(T m, T n) {
  T ret = math_P(m, n);
  for (T i = 2; i <= n; i++) {
    ret /= i;
  }
  return ret;
}
template <class T> T math_gcd(T a, T b) {
  if (b == 0) {
    return a;
  } else {
    return math_gcd(b, a % b);
  }
}

// constexpr ll MOD = 1000000007;	// 10^9+7
constexpr ll MOD = 998244353;

/*****/

void Main() {
  ll N;
  cin >> N;

  ll ret = 0;
  for (ll a = 1; a * a <= N; ++a) {
    // debug_cout(a);

    if (N % a == 0) {
      ll k = N / a - 1;

      if (N % k == N / k) {
        ret += k;
      }
    }
  }

  cout << ret;
}

/*****/

int main() {
  std::ios::sync_with_stdio(false);
  std::cin.tie(0);

  // std::cout << std::fixed << std::setprecision(10);

  /**
  while (true)
  {
          Main();
          std::cerr << flush;
          cout << endl;
  }
  /*/
  Main();
  std::cerr << flush;
  cout << endl;
  /**/

  return 0;
}


Fixed submission:

/*
        @・ω・@
*/

/*****/

#include <algorithm>
#include <cmath>
#include <functional>
#include <iomanip> //cout << fixed << setprecision(桁数);
#include <iostream>
#include <map>
#include <queue>
#include <stack>
#include <stdexcept>
#include <string>
#include <vector>

// #define int long long

using namespace std;
using ll = long long;
using ld = long double;
using pll = pair<long long, long long>;
template <class T> using vec = vector<T>;

#define debug(x) (std::cerr << x)
#define debugln(x) (std::cerr << x << "\n")
#define debug_tab(n, x) (std::cerr << strMulti("\t", n) << (x) << "\n")
#define debug_cout(x) (std::cerr << #x << " : " << (x) << "\n")
#define debug_coutvec(x)                                                       \
  std::cerr << #x << " : ";                                                    \
  _debug_coutvec(x)
#define debug_tabcout(n, x)                                                    \
  (std::cerr << strMulti("\t", n) << #x << " : " << (x) << "\n")
#define debug_headcout(h, x) (std::cerr << h << " : " << (x) << "\n")
#define debug_tabheadcout(n, h, x)                                             \
  (std::cerr << strMulti("\t", n) << h << " : " << (x) << "\n")

#define rep(i, n) for (int i = 0, i##_len = (n); i < i##_len; ++i)
#define rep1(i, n) for (int i = 1, i##_len = (n); i <= i##_len; ++i)
#define rrep(i, n) for (int i = (n)-1; i >= 0; --i)
#define rrep1(i, n) for (int i = (n); i > 0; --i)
#define step(i, a, n) for (int i = (a), i##_len = (a) + (n); i < i##_len; ++i)
#define rstep(i, a, n)                                                         \
  for (int i = (a) + (n)-1, i##_len = (a); i >= i##_len; --i)
#define range(i, a, b) for (int i = (a), i##_len = (b); i < i##_len; ++i)
#define rrange(i, a, b) for (int i = (b)-1, i##_len = (a); i >= i##_len; --i)
#define repll(i, n) for (ll i = 0, i##_len = (n); i < i##_len; ++i)
#define rep1ll(i, n) for (ll i = 1, i##_len = (n); i <= i##_len; ++i)
#define rrepll(i, n) for (ll i = (n)-1; i >= 0; --i)
#define rrep1ll(i, n) for (ll i = (n); i > 0; --i)
#define stepll(i, a, n) for (ll i = (a), i##_len = (a) + (n); i < i##_len; ++i)
#define rstepll(i, a, n)                                                       \
  for (ll i = (a) + (n)-1, i##_len = (a); i >= i##_len; --i)
#define rangell(i, a, b) for (ll i = (a), i##_len = (b); i < i##_len; ++i)
#define rrangell(i, a, b) for (ll i = (b)-1, i##_len = (a); i >= i##_len; --i)
#define all(x) (x).begin(), (x).end()
#define pair(a, b) make_pair(a, b)
std::string strMulti(std::string t, int n) {
  std::string out = "";
  for (int i = 0; i < n; i++) {
    out += t;
  }
  return out;
}
template <class T> void _debug_coutvec(vector<T> ar, string space = " ") {
  rep(i, ar.size()) { debug(ar[i] << space); }
  debugln("");
}
constexpr int INF = 2000000000; // 2*10^9
constexpr ll INFL = 1ll << 60ll;

template <class T> bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
template <class T> bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
template <class T> T divup(T a, T b) {
  if (a % b == 0) {
    return a / b;
  }
  return a / b + 1;
}
template <class T> bool cmp_2nd(pair<T, T> a, pair<T, T> b) {
  if (a.second != b.second) {
    return a.second < b.second;
  }
  return a.first < b.first;
}
template <class T> T mod_pow(T x, T n, const T &p) {
  T ret = 1;
  while (n > 0) {
    if (n & 1) {
      (ret *= x) %= p;
    }
    (x *= x) %= p;
    n >>= 1;
  }
  return ret;
}
template <class T> T math_P(T m, T n) {
  T ret = 1;
  for (T i = m; i > m - n; i--) {
    ret *= i;
  }
  return ret;
}
template <class T> T math_C(T m, T n) {
  T ret = math_P(m, n);
  for (T i = 2; i <= n; i++) {
    ret /= i;
  }
  return ret;
}
template <class T> T math_gcd(T a, T b) {
  if (b == 0) {
    return a;
  } else {
    return math_gcd(b, a % b);
  }
}

// constexpr ll MOD = 1000000007;	// 10^9+7
constexpr ll MOD = 998244353;

/*****/

void Main() {
  ll N;
  cin >> N;

  if (N == 1) {
    cout << 0;
    return;
  }

  ll ret = 0;
  for (ll a = 1; a * a <= N; ++a) {
    // debug_cout(a);

    if (N % a == 0) {
      ll k = N / a - 1;

      if (N % k == N / k) {
        ret += k;
      }
    }
  }

  cout << ret;
}

/*****/

int main() {
  std::ios::sync_with_stdio(false);
  std::cin.tie(0);

  // std::cout << std::fixed << std::setprecision(10);

  /**
  while (true)
  {
          Main();
          std::cerr << flush;
          cout << endl;
  }
  /*/
  Main();
  std::cerr << flush;
  cout << endl;
  /**/

  return 0;
}