Problem p03004 (C++)

Buggy submission (status: Time Limit Exceeded):
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using VI = vector<int>;
using VL = vector<ll>;
template <class T> using PQ = priority_queue<T, vector<T>, greater<T>>;
#define FOR(i, a, n) for (int(i) = (a); (i) < (n); ++(i))
#define eFOR(i, a, n) for (int(i) = (a); (i) <= (n); ++(i))
#define rFOR(i, a, n) for (int(i) = (n)-1; (i) >= (a); --(i))
#define erFOR(i, a, n) for (int(i) = (n); (i) >= (a); --(i))
#define each(i, a) for (auto &i : a)
#define SORT(i) sort((i).begin(), (i).end())
#define rSORT(i, a) sort((i).begin(), (i).end(), (a))
#define all(i) (i).begin(), (i).end()
#define out(y, x) ((y) < 0 || h <= (y) || (x) < 0 || w <= (x))
#define line cout << "------------------------\n"
#define ENDL(i, n) ((i) == (n)-1 ? "\n" : " ")
#define stop system("pause") // comment out this on AOJ.
constexpr ll INF = 1000000000;
constexpr ll LLINF = 1LL << 60;
constexpr ll mod = 1000000007;
constexpr ll MOD = 998244353;
constexpr ld eps = 1e-10; // 1e-9?
constexpr ld pi = 3.1415926535897932;
template <class T> inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
template <class T> inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
inline void init() {
  cin.tie(nullptr);
  cout.tie(nullptr);
  ios::sync_with_stdio(false);
  cout << fixed << setprecision(15);
}
template <class T> inline istream &operator>>(istream &is, vector<T> &v) {
  for (auto &elemnt : v)
    is >> elemnt;
  return is;
}
template <class T, class U>
inline istream &operator>>(istream &is, pair<T, U> &p) {
  is >> p.first >> p.second;
  return is;
}
template <class T> inline vector<T> vec(size_t a) { return vector<T>(a); }
template <class T> inline vector<T> defvec(T def, size_t a) {
  return vector<T>(a, def);
}
template <class T, class... Ts> inline auto vec(size_t a, Ts... ts) {
  return vector<decltype(vec<T>(ts...))>(a, vec<T>(ts...));
}
template <class T, class... Ts> inline auto defvec(T def, size_t a, Ts... ts) {
  return vector<decltype(defvec<T>(def, ts...))>(a, defvec<T>(def, ts...));
}

int main() {
  init();

  int n;
  cin >> n;
  vector<ld> x(n), y(n);
  vector<char> d(n);
  FOR(i, 0, n) cin >> x[i] >> y[i] >> d[i];

  map<char, ld> Xdir, Ydir;
  Xdir['R'] = 1, Xdir['L'] = -1;
  Ydir['U'] = 1, Ydir['D'] = -1;
  function<ld(ld)> f = [&](ld t) {
    ld Xmax = -LLINF, Xmin = LLINF;
    ld Ymax = -LLINF, Ymin = LLINF;
    FOR(i, 0, n) {
      ld nx = x[i] + t * Xdir[d[i]];
      ld ny = y[i] + t * Ydir[d[i]];
      chmax(Xmax, nx), chmin(Xmin, nx);
      chmax(Ymax, ny), chmin(Ymin, ny);
    }
    return (Xmax - Xmin) * (Ymax - Ymin);
  };

  ld l = 0, r = INF;
  FOR(i, 0, 1000) {
    ld m1 = (l * 2 + r) / 3, m2 = (l + r * 2) / 3;
    if (f(m1) < f(m2))
      r = m2;
    else
      l = m1;
  }
  cout << f(l) << "\n";
}

Fixed submission:
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using VI = vector<int>;
using VL = vector<ll>;
template <class T> using PQ = priority_queue<T, vector<T>, greater<T>>;
#define FOR(i, a, n) for (int(i) = (a); (i) < (n); ++(i))
#define eFOR(i, a, n) for (int(i) = (a); (i) <= (n); ++(i))
#define rFOR(i, a, n) for (int(i) = (n)-1; (i) >= (a); --(i))
#define erFOR(i, a, n) for (int(i) = (n); (i) >= (a); --(i))
#define each(i, a) for (auto &i : a)
#define SORT(i) sort((i).begin(), (i).end())
#define rSORT(i, a) sort((i).begin(), (i).end(), (a))
#define all(i) (i).begin(), (i).end()
#define out(y, x) ((y) < 0 || h <= (y) || (x) < 0 || w <= (x))
#define line cout << "------------------------\n"
#define ENDL(i, n) ((i) == (n)-1 ? "\n" : " ")
#define stop system("pause") // comment out this on AOJ.
constexpr ll INF = 1000000000;
constexpr ll LLINF = 1LL << 60;
constexpr ll mod = 1000000007;
constexpr ll MOD = 998244353;
constexpr ld eps = 1e-10; // 1e-9?
constexpr ld pi = 3.1415926535897932;
template <class T> inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
template <class T> inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
inline void init() {
  cin.tie(nullptr);
  cout.tie(nullptr);
  ios::sync_with_stdio(false);
  cout << fixed << setprecision(15);
}
template <class T> inline istream &operator>>(istream &is, vector<T> &v) {
  for (auto &elemnt : v)
    is >> elemnt;
  return is;
}
template <class T, class U>
inline istream &operator>>(istream &is, pair<T, U> &p) {
  is >> p.first >> p.second;
  return is;
}
template <class T> inline vector<T> vec(size_t a) { return vector<T>(a); }
template <class T> inline vector<T> defvec(T def, size_t a) {
  return vector<T>(a, def);
}
template <class T, class... Ts> inline auto vec(size_t a, Ts... ts) {
  return vector<decltype(vec<T>(ts...))>(a, vec<T>(ts...));
}
template <class T, class... Ts> inline auto defvec(T def, size_t a, Ts... ts) {
  return vector<decltype(defvec<T>(def, ts...))>(a, defvec<T>(def, ts...));
}

int main() {
  init();

  int n;
  cin >> n;
  vector<ld> x(n), y(n);
  vector<char> d(n);
  FOR(i, 0, n) cin >> x[i] >> y[i] >> d[i];

  map<char, ld> Xdir, Ydir;
  Xdir['R'] = 1, Xdir['L'] = -1;
  Ydir['U'] = 1, Ydir['D'] = -1;
  function<ld(ld)> f = [&](ld t) {
    ld Xmax = -LLINF, Xmin = LLINF;
    ld Ymax = -LLINF, Ymin = LLINF;
    FOR(i, 0, n) {
      ld nx = x[i] + t * Xdir[d[i]];
      ld ny = y[i] + t * Ydir[d[i]];
      chmax(Xmax, nx), chmin(Xmin, nx);
      chmax(Ymax, ny), chmin(Ymin, ny);
    }
    return (Xmax - Xmin) * (Ymax - Ymin);
  };

  ld l = 0, r = INF;
  FOR(i, 0, 500) {
    ld m1 = (l * 2 + r) / 3, m2 = (l + r * 2) / 3;
    if (f(m1) < f(m2))
      r = m2;
    else
      l = m1;
  }
  cout << f(l) << "\n";
}