Problem p03004 (C++)

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

#define _overload(_1, _2, _3, name, ...) name
#define _rep(i, n) _range(i, 0, n)
#define _range(i, a, b) for (int i = (int)(a); i < (int)(b); ++i)
#define rep(...) _overload(__VA_ARGS__, _range, _rep, )(__VA_ARGS__)

#define _rrep(i, n) _rrange(i, n, 0)
#define _rrange(i, a, b) for (int i = (int)(a)-1; i >= (int)(b); --i)
#define rrep(...) _overload(__VA_ARGS__, _rrange, _rrep, )(__VA_ARGS__)

#define _all(arg) begin(arg), end(arg)
#define uniq(arg) sort(_all(arg)), (arg).erase(unique(_all(arg)), end(arg))
#define getidx(ary, key) lower_bound(_all(ary), key) - begin(ary)
#define clr(a, b) memset((a), (b), sizeof(a))
#define bit(n) (1LL << (n))

// #define DEBUG

#ifdef DEBUG
#define dump(...) fprintf(stderr, __VA_ARGS__)
#else
#define dump(...)
#endif

template <class T> bool chmax(T &a, const T &b) {
  return (a < b) ? (a = b, 1) : 0;
}
template <class T> bool chmin(T &a, const T &b) {
  return (b < a) ? (a = b, 1) : 0;
}

using namespace std;
using ll = long long;
using vi = vector<int>;
using vll = vector<ll>;

const double EPS = 1e-10;
const double PI = acos(-1.0);
const int inf = (int)1e9;
const ll mod = 1000000007LL;
const int dx[4] = {1, 0, -1, 0};
const int dy[4] = {0, 1, 0, -1};

ll extgcd(ll a, ll b, ll &x, ll &y) {
  x = 1, y = 0;
  ll g = a;
  if (b != 0)
    g = extgcd(b, a % b, y, x), y -= a / b * x;
  return g;
}
ll ADD(const ll &a, const ll &b, const ll &mod) { return (a + b) % mod; }
ll SUB(const ll &a, const ll &b, const ll &mod) { return (a - b + mod) % mod; }
ll MUL(const ll &a, const ll &b, const ll &mod) { return (1LL * a * b) % mod; }
ll DIV(const ll &a, const ll &b, const ll &mod) {
  ll x, y;
  extgcd(b, mod, x, y);
  return MUL(a, (x + mod) % mod, mod);
}

random_device rd;
mt19937 mt(rd());
uniform_int_distribution<int> dice(1, 6);
uniform_real_distribution<double> score(0.0, 10.0);

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

  int n;
  cin >> n;
  map<char, vi> x;
  map<char, vi> y;
  for (auto &c : "RLUD") {
    x[c] = vi(1, -inf), y[c] = vi(1, -inf);
  }
  rep(i, n) {
    int xx, yy;
    char d;
    cin >> xx >> yy >> d;
    x[d].emplace_back(xx);
    y[d].emplace_back(yy);
  }

  map<char, int> xmax, xmin, ymax, ymin;
  for (auto &c : "RLUD") {
    xmax[c] = *max_element(_all(x[c]));
    ymax[c] = *max_element(_all(y[c]));

    x[c][0] = inf, y[c][0] = inf;
    xmin[c] = *min_element(_all(x[c]));
    ymin[c] = *min_element(_all(y[c]));
  }

  int xmab = max(xmax['U'], xmax['D']);
  int xmib = min(xmin['U'], xmin['D']);
  int ymab = max(ymax['R'], ymax['L']);
  int ymib = min(ymin['R'], ymin['L']);

  using R = double;
  R res = 1LL << 61;
  rep(_, 4 * ((int)1e8 + 1)) {
    R loop = 0.5 * _;
    R xma = max(1. * xmab, max(xmax['R'] + loop, xmax['L'] - loop));
    R xmi = min(1. * xmib, min(xmin['R'] + loop, xmin['L'] - loop));
    R yma = max(1. * ymab, max(ymax['U'] + loop, ymax['D'] - loop));
    R ymi = min(1. * ymib, min(ymin['U'] + loop, ymin['D'] - loop));

    chmin(res, (xma - xmi) * (yma - ymi));
  }

  cout.precision(20);
  cout << fixed << res << endl;

  return 0;
}


Fixed submission:
#include <bits/stdc++.h>

#define _overload(_1, _2, _3, name, ...) name
#define _rep(i, n) _range(i, 0, n)
#define _range(i, a, b) for (int i = (int)(a); i < (int)(b); ++i)
#define rep(...) _overload(__VA_ARGS__, _range, _rep, )(__VA_ARGS__)

#define _rrep(i, n) _rrange(i, n, 0)
#define _rrange(i, a, b) for (int i = (int)(a)-1; i >= (int)(b); --i)
#define rrep(...) _overload(__VA_ARGS__, _rrange, _rrep, )(__VA_ARGS__)

#define _all(arg) begin(arg), end(arg)
#define uniq(arg) sort(_all(arg)), (arg).erase(unique(_all(arg)), end(arg))
#define getidx(ary, key) lower_bound(_all(ary), key) - begin(ary)
#define clr(a, b) memset((a), (b), sizeof(a))
#define bit(n) (1LL << (n))

// #define DEBUG

#ifdef DEBUG
#define dump(...) fprintf(stderr, __VA_ARGS__)
#else
#define dump(...)
#endif

template <class T> bool chmax(T &a, const T &b) {
  return (a < b) ? (a = b, 1) : 0;
}
template <class T> bool chmin(T &a, const T &b) {
  return (b < a) ? (a = b, 1) : 0;
}

using namespace std;
using ll = long long;
using vi = vector<int>;
using vll = vector<ll>;

const double EPS = 1e-10;
const double PI = acos(-1.0);
const int inf = (int)1e9;
const ll mod = 1000000007LL;
const int dx[4] = {1, 0, -1, 0};
const int dy[4] = {0, 1, 0, -1};

ll extgcd(ll a, ll b, ll &x, ll &y) {
  x = 1, y = 0;
  ll g = a;
  if (b != 0)
    g = extgcd(b, a % b, y, x), y -= a / b * x;
  return g;
}
ll ADD(const ll &a, const ll &b, const ll &mod) { return (a + b) % mod; }
ll SUB(const ll &a, const ll &b, const ll &mod) { return (a - b + mod) % mod; }
ll MUL(const ll &a, const ll &b, const ll &mod) { return (1LL * a * b) % mod; }
ll DIV(const ll &a, const ll &b, const ll &mod) {
  ll x, y;
  extgcd(b, mod, x, y);
  return MUL(a, (x + mod) % mod, mod);
}

random_device rd;
mt19937 mt(rd());
uniform_int_distribution<int> dice(1, 6);
uniform_real_distribution<double> score(0.0, 10.0);

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

  int n;
  cin >> n;
  map<char, vi> x;
  map<char, vi> y;
  for (auto &c : "RLUD") {
    x[c] = vi(1, -inf), y[c] = vi(1, -inf);
  }
  rep(i, n) {
    int xx, yy;
    char d;
    cin >> xx >> yy >> d;
    x[d].emplace_back(xx);
    y[d].emplace_back(yy);
  }

  vi xmax(300), xmin(300), ymax(300), ymin(300);
  for (auto &c : "RLUD") {
    xmax[c] = *max_element(_all(x[c]));
    ymax[c] = *max_element(_all(y[c]));

    x[c][0] = inf, y[c][0] = inf;
    xmin[c] = *min_element(_all(x[c]));
    ymin[c] = *min_element(_all(y[c]));
  }

  int xmab = max(xmax['U'], xmax['D']);
  int xmib = min(xmin['U'], xmin['D']);
  int ymab = max(ymax['R'], ymax['L']);
  int ymib = min(ymin['R'], ymin['L']);

  using R = double;
  R res = 1LL << 61;
  rep(_, 4 * ((int)1e8 + 1)) {
    R loop = 0.5 * _;
    R xma = max(1. * xmab, max(xmax['R'] + loop, xmax['L'] - loop));
    R xmi = min(1. * xmib, min(xmin['R'] + loop, xmin['L'] - loop));
    R yma = max(1. * ymab, max(ymax['U'] + loop, ymax['D'] - loop));
    R ymi = min(1. * ymib, min(ymin['U'] + loop, ymin['D'] - loop));

    chmin(res, (xma - xmi) * (yma - ymi));
  }

  cout.precision(20);
  cout << fixed << res << endl;

  return 0;
}