Problem p03050 (C++)

Buggy submission (status: Time Limit Exceeded):
#include <bits/stdc++.h>
using namespace std;

#define NDEBUG
#include <cassert>

typedef long long ll;
typedef long double Double;
typedef unsigned long long ull;
typedef pair<int, int> ii;
typedef pair<ll, ll> llll;
typedef pair<double, double> dd;

typedef vector<int> vi;
typedef vector<vector<int>> vvi;
typedef vector<ii> vii;
typedef vector<vector<ii>> vvii;
typedef vector<ll> vll;
typedef vector<string> vs;
typedef vector<double> vd;
typedef vector<long double> vD;

#define sz(a) int((a).size())
#define pb push_back
#define eb emplace_back
#define FOR(var, from, to) for (int var = (from); var <= (to); ++var)
#define rep(var, n) for (int var = 0; var < (n); ++var)
#define rep1(var, n) for (int var = 1; var <= (n); ++var)
#define repC2(vari, varj, n)                                                   \
  for (int vari = 0; vari < (n)-1; ++vari)                                     \
    for (int varj = vari + 1; varj < (n); ++varj)
#define ALL(c) (c).begin(), (c).end()
#define RALL(c) (c).rbegin(), (c).rend()
#define tr(i, c) for (auto i = (c).begin(); i != (c).end(); ++i)
#define found(s, e) ((s).find(e) != (s).end())
#define mset(arr, val) memset(arr, val, sizeof(arr))
#define mid(x, y) ((x) + ((y) - (x)) / 2)
#define IN(x, a, b) ((a) <= (x) && (x) <= (b))
#define cons make_pair

#define PQ(T) priority_queue<T>
#define RPQ(T) priority_queue<T, vector<T>, greater<T>>

template <class T> inline void amin(T &a, T const &b) { a = min(a, b); }
template <class T> inline void amax(T &a, T const &b) { a = max(a, b); }

inline ll square(ll x) { return x * x; }
inline ll gcd(ll a, ll b) {
  while (a)
    swap(a, b %= a);
  return b;
}
template <typename T> inline T mod(T a, T b) { return ((a % b) + b) % b; }

const ll MOD = 1000000007LL;

ll ADD(ll x, ll y) { return (x + y) % MOD; }
ll SUB(ll x, ll y) { return (x - y + MOD) % MOD; }
ll MUL(ll x, ll y) { return x * y % MOD; }
ll POW(ll x, ll e) {
  ll v = 1;
  for (; e; x = MUL(x, x), e >>= 1)
    if (e & 1)
      v = MUL(v, x);
  return v;
}
ll DIV(ll x, ll y) { /*assert(y%MOD!=0);*/
  return MUL(x, POW(y, MOD - 2));
}

ll solve(ll N) {
  ll ans = 0;
  for (ll x = 1;; ++x) {
    if (N % x)
      continue;
    ll m = N / x - 1;
    if (x >= m) {
      break;
    }
    ans += m;
  }
  return ans;
}

int main() {
  ll N;
  cin >> N;
  cout << solve(N) << endl;
  return 0;
}


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

#define NDEBUG
#include <cassert>

typedef long long ll;
typedef long double Double;
typedef unsigned long long ull;
typedef pair<int, int> ii;
typedef pair<ll, ll> llll;
typedef pair<double, double> dd;

typedef vector<int> vi;
typedef vector<vector<int>> vvi;
typedef vector<ii> vii;
typedef vector<vector<ii>> vvii;
typedef vector<ll> vll;
typedef vector<string> vs;
typedef vector<double> vd;
typedef vector<long double> vD;

#define sz(a) int((a).size())
#define pb push_back
#define eb emplace_back
#define FOR(var, from, to) for (int var = (from); var <= (to); ++var)
#define rep(var, n) for (int var = 0; var < (n); ++var)
#define rep1(var, n) for (int var = 1; var <= (n); ++var)
#define repC2(vari, varj, n)                                                   \
  for (int vari = 0; vari < (n)-1; ++vari)                                     \
    for (int varj = vari + 1; varj < (n); ++varj)
#define ALL(c) (c).begin(), (c).end()
#define RALL(c) (c).rbegin(), (c).rend()
#define tr(i, c) for (auto i = (c).begin(); i != (c).end(); ++i)
#define found(s, e) ((s).find(e) != (s).end())
#define mset(arr, val) memset(arr, val, sizeof(arr))
#define mid(x, y) ((x) + ((y) - (x)) / 2)
#define IN(x, a, b) ((a) <= (x) && (x) <= (b))
#define cons make_pair

#define PQ(T) priority_queue<T>
#define RPQ(T) priority_queue<T, vector<T>, greater<T>>

template <class T> inline void amin(T &a, T const &b) { a = min(a, b); }
template <class T> inline void amax(T &a, T const &b) { a = max(a, b); }

inline ll square(ll x) { return x * x; }
inline ll gcd(ll a, ll b) {
  while (a)
    swap(a, b %= a);
  return b;
}
template <typename T> inline T mod(T a, T b) { return ((a % b) + b) % b; }

const ll MOD = 1000000007LL;

ll ADD(ll x, ll y) { return (x + y) % MOD; }
ll SUB(ll x, ll y) { return (x - y + MOD) % MOD; }
ll MUL(ll x, ll y) { return x * y % MOD; }
ll POW(ll x, ll e) {
  ll v = 1;
  for (; e; x = MUL(x, x), e >>= 1)
    if (e & 1)
      v = MUL(v, x);
  return v;
}
ll DIV(ll x, ll y) { /*assert(y%MOD!=0);*/
  return MUL(x, POW(y, MOD - 2));
}

ll solve(ll N) {
  ll ans = 0;
  ll sq = sqrt(N);
  for (ll x = 1; x <= sq + 3; ++x) {
    if (N % x)
      continue;
    ll m = N / x - 1;
    if (x >= m) {
      break;
    }
    ans += m;
  }
  return ans;
}

int main() {
  ll N;
  cin >> N;
  cout << solve(N) << endl;
  return 0;
}