Problem p03241 (C++)

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

using ull = unsigned long long;
using ll = long long;

#define REP(i, n) for (int i = 0; i < n; i++)
#define REPR(i, n) for (int i = n; i >= 0; i--)
#define FOR(i, m, n) for (int i = m; i < n; i++)
#define pb push_back
#define fill(x, y) memset(x, y, sizeof(x))
#define even(x) x % 2 == 0
#define odd(x) x % 2 != 0
#define all(x) x.begin(), x.end()
#define pcnt __builtin_popcount
#define buli(x) __builtin_popcountll(x)
#define F first
#define S second
#define UNIQUE(v) v.erase(unique(v.begin(), v.end()), v.end());
#define IN1(x)                                                                 \
  ll x;                                                                        \
  cin >> x;

// these functions return the position of result of Binary Search.
#define LB(s, t, x) (int)(lower_bound(s, t, x) - s)
#define UB(s, t, x) (int)(upper_bound(s, t, x) - s)

ll qp(ll a, ll b, int mo) {
  ll ans = 1;
  do {
    if (b & 1)
      ans = 1ll * ans * a % mo;
    a = 1ll * a * a % mo;
  } while (b >>= 1);
  return ans;
}
ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; }
ll lcm(ll a, ll b) {
  ll temp = gcd(a, b);
  return temp ? (a / temp * b) : 0;
}
int mDays[] = {31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
int dx8[] = {1, -1, 0, 0, 1, 1, -1, -1}, dy8[] = {0, 0, -1, 1, -1, 1, -1, 1};

template <typename T> vector<T> make_v(size_t a) { return vector<T>(a); }
template <typename T, typename... Ts>
auto make_v(size_t a, size_t b, Ts... ts) {
  return vector<decltype(make_v<T>(b, ts...))>(a, make_v<T>(b, ts...));
}
template <typename T, typename V>
typename enable_if<is_class<T>::value == 0>::type fill_v(T &t, const V &v) {
  t = v;
}
template <typename T, typename V>
typename enable_if<is_class<T>::value != 0>::type fill_v(T &t, const V &v) {
  for (auto &e : t)
    fill_v(e, v);
}
// auto dp = make_v<int>(4, h, w);
// fill_v(dp, 0);

const ll INF_LL = (1ll << 60);
const int INF_INT = (int)1e9;
const ll MOD_CONST = (ll)(1e9 + 7);

template <typename T> vector<T> pows(int b, int n) {
  vector<T> ret;
  T x = 1;
  while (ret.size() < n) {
    ret.push_back(x);
    x *= b;
  }
  return ret;
}
// find string "from" in "str", and replace them to "to"
void strReplace(std::string &str, const std::string &from,
                const std::string &to) {
  std::string::size_type pos = 0;
  while (pos = str.find(from, pos), pos != std::string::npos) {
    str.replace(pos, from.length(), to);
    pos += to.length();
  }
}
template <class T> bool chmax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> bool chmin(T &a, const T &b) {
  if (b < a) {
    a = b;
    return 1;
  }
  return 0;
}

inline tuple<ll, ll> rotate45(tuple<ll, ll> point) {
  ll x = get<0>(point), y = get<1>(point);
  return tuple<ll, ll>(x + y, x - y);
}
inline bool rangeCheck2D(int nx, int ny, int Width, int Height) {
  return nx >= 0 and nx < Width and ny >= 0 and ny < Height;
}

template <typename T> vector<T> INPA(ll n) {
  vector<T> x;
  REP(i, n) {
    T tmp;
    cin >> tmp;
    x.push_back(tmp);
  }
  return move(x);
}
template <typename T> void out(T o) { cout << o << endl; }
template <typename T> void out(vector<T> &out) {
  REP(i, (int)out.size()) {
    cout << out[i];
    if (i == (int)out.size() - 1)
      cout << endl;
    else
      cout << " ";
  }
}
template <typename T> void out(vector<vector<T>> o) {
  REP(i, o.size()) out(o[i]);
}
void YesNo(bool f) { cout << (f ? "Yes" : "No") << endl; }
void YESNO(bool f) { cout << (f ? "YES" : "NO") << endl; }

int main(void) {
  cin.tie(0);
  ios::sync_with_stdio(0);
  cout << fixed << setprecision(20);

  IN1(N);
  IN1(M);

  ll sm = ll(sqrt(M));
  ll ans = 1;

  for (int i = M / N; i >= 1; i--) {
    if (M % i == 0) {
      chmax(ans, ll(i));
    }
  }
  out(ans);

  return 0;
}

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

using ull = unsigned long long;
using ll = long long;

#define REP(i, n) for (int i = 0; i < n; i++)
#define REPR(i, n) for (int i = n; i >= 0; i--)
#define FOR(i, m, n) for (int i = m; i < n; i++)
#define pb push_back
#define fill(x, y) memset(x, y, sizeof(x))
#define even(x) x % 2 == 0
#define odd(x) x % 2 != 0
#define all(x) x.begin(), x.end()
#define pcnt __builtin_popcount
#define buli(x) __builtin_popcountll(x)
#define F first
#define S second
#define UNIQUE(v) v.erase(unique(v.begin(), v.end()), v.end());
#define IN1(x)                                                                 \
  ll x;                                                                        \
  cin >> x;

// these functions return the position of result of Binary Search.
#define LB(s, t, x) (int)(lower_bound(s, t, x) - s)
#define UB(s, t, x) (int)(upper_bound(s, t, x) - s)

ll qp(ll a, ll b, int mo) {
  ll ans = 1;
  do {
    if (b & 1)
      ans = 1ll * ans * a % mo;
    a = 1ll * a * a % mo;
  } while (b >>= 1);
  return ans;
}
ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; }
ll lcm(ll a, ll b) {
  ll temp = gcd(a, b);
  return temp ? (a / temp * b) : 0;
}
int mDays[] = {31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
int dx8[] = {1, -1, 0, 0, 1, 1, -1, -1}, dy8[] = {0, 0, -1, 1, -1, 1, -1, 1};

template <typename T> vector<T> make_v(size_t a) { return vector<T>(a); }
template <typename T, typename... Ts>
auto make_v(size_t a, size_t b, Ts... ts) {
  return vector<decltype(make_v<T>(b, ts...))>(a, make_v<T>(b, ts...));
}
template <typename T, typename V>
typename enable_if<is_class<T>::value == 0>::type fill_v(T &t, const V &v) {
  t = v;
}
template <typename T, typename V>
typename enable_if<is_class<T>::value != 0>::type fill_v(T &t, const V &v) {
  for (auto &e : t)
    fill_v(e, v);
}
// auto dp = make_v<int>(4, h, w);
// fill_v(dp, 0);

const ll INF_LL = (1ll << 60);
const int INF_INT = (int)1e9;
const ll MOD_CONST = (ll)(1e9 + 7);

template <typename T> vector<T> pows(int b, int n) {
  vector<T> ret;
  T x = 1;
  while (ret.size() < n) {
    ret.push_back(x);
    x *= b;
  }
  return ret;
}
// find string "from" in "str", and replace them to "to"
void strReplace(std::string &str, const std::string &from,
                const std::string &to) {
  std::string::size_type pos = 0;
  while (pos = str.find(from, pos), pos != std::string::npos) {
    str.replace(pos, from.length(), to);
    pos += to.length();
  }
}
template <class T> bool chmax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> bool chmin(T &a, const T &b) {
  if (b < a) {
    a = b;
    return 1;
  }
  return 0;
}

inline tuple<ll, ll> rotate45(tuple<ll, ll> point) {
  ll x = get<0>(point), y = get<1>(point);
  return tuple<ll, ll>(x + y, x - y);
}
inline bool rangeCheck2D(int nx, int ny, int Width, int Height) {
  return nx >= 0 and nx < Width and ny >= 0 and ny < Height;
}

template <typename T> vector<T> INPA(ll n) {
  vector<T> x;
  REP(i, n) {
    T tmp;
    cin >> tmp;
    x.push_back(tmp);
  }
  return move(x);
}
template <typename T> void out(T o) { cout << o << endl; }
template <typename T> void out(vector<T> &out) {
  REP(i, (int)out.size()) {
    cout << out[i];
    if (i == (int)out.size() - 1)
      cout << endl;
    else
      cout << " ";
  }
}
template <typename T> void out(vector<vector<T>> o) {
  REP(i, o.size()) out(o[i]);
}
void YesNo(bool f) { cout << (f ? "Yes" : "No") << endl; }
void YESNO(bool f) { cout << (f ? "YES" : "NO") << endl; }

int main(void) {
  cin.tie(0);
  ios::sync_with_stdio(0);
  cout << fixed << setprecision(20);

  IN1(N);
  IN1(M);

  ll sm = ll(sqrt(M));
  ll ans = 1;

  for (int i = M / N; i >= 1; i--) {
    if (M % i == 0) {
      out(i);
      return 0;
    }
  }
  out(ans);

  return 0;
}