Problem p02605 (C++) — buggy submission, verdict: Time Limit Exceeded

#include <algorithm>
#include <cmath>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <string>
#define _USE_MATH_DEFINES
#include <complex>
#include <functional>
#include <math.h>
using namespace std;

#define rep(i, x) for (ll i = 0; i < x; i++)
#define repn(i, x) for (ll i = 1; i <= x; i++)

typedef long long ll;
const ll INF = 1e18 + 1e18;
const ll MOD = 1000000007;
const ll MAX = 4000001;
const long double eps = 1E-14;

ll max(ll a, ll b) {
  if (a > b) {
    return a;
  }
  return b;
}

ll min(ll a, ll b) {
  if (a > b) {
    return b;
  }
  return a;
}

ll gcd(ll a, ll b) {
  if (b == 0) {
    return a;
  }
  if (a < b) {
    return gcd(b, a);
  }
  return gcd(b, a % b);
}

ll lcm(ll a, ll b) { return a / gcd(a, b) * b; }

struct edge {
  ll ind;
  ll fr;
  ll to;
  ll d;
};

class mint {
  long long x;

public:
  mint(long long x = 0) : x((x % MOD + MOD) % MOD) {}
  mint operator-() const { return mint(-x); }
  mint &operator+=(const mint &a) {
    if ((x += a.x) >= MOD)
      x -= MOD;
    return *this;
  }
  mint &operator-=(const mint &a) {
    if ((x += MOD - a.x) >= MOD)
      x -= MOD;
    return *this;
  }
  mint &operator*=(const mint &a) {
    (x *= a.x) %= MOD;
    return *this;
  }
  mint operator+(const mint &a) const {
    mint res(*this);
    return res += a;
  }
  mint operator-(const mint &a) const {
    mint res(*this);
    return res -= a;
  }
  mint operator*(const mint &a) const {
    mint res(*this);
    return res *= a;
  }

  mint pow(ll t) const {
    if (!t)
      return 1;
    mint a = pow(t >> 1);
    a *= a;
    if (t & 1)
      a *= *this;
    return a;
  }

  // for prime MOD
  mint inv() const { return pow(MOD - 2); }
  mint &operator/=(const mint &a) { return (*this) *= a.inv(); }
  mint operator/(const mint &a) const {
    mint res(*this);
    return res /= a;
  }

  friend ostream &operator<<(ostream &os, const mint &m) {
    os << m.x;
    return os;
  }
};

mint pw(mint a, ll b) {
  if (b == 0) {
    return 1;
  }
  mint ret = pw(a, b >> 1);
  ret *= ret;
  if (b & 1) {
    ret *= a;
  }
  return ret;
}

typedef vector<ll> vll;
typedef vector<vector<ll>> vvll;
typedef vector<vector<vector<ll>>> vvvll;

typedef vector<mint> vmint;
typedef vector<vector<mint>> vvmint;
typedef vector<vector<vector<mint>>> vvvmint;

//////////////////////////////////////

int main() {
  int N;
  cin >> N;
  vector<int> X(N + 1), Y(N + 1), U(N + 1);
  repn(i, N) {
    cin >> X[i] >> Y[i];
    char c;
    cin >> c;
    if (c == 'L') {
      U[i] = 0;
    }
    if (c == 'R') {
      U[i] = 1;
    }
    if (c == 'U') {
      U[i] = 2;
    }
    if (c == 'D') {
      U[i] = 3;
    }
  }

  vector<map<int, set<int>>> x(4), y(4), xmy(4), xpy(4);

  repn(i, N) {
    x[U[i]][X[i]].insert(Y[i]);
    y[U[i]][Y[i]].insert(X[i]);
    xpy[U[i]][X[i] + Y[i]].insert(X[i]);
    xmy[U[i]][X[i] - Y[i]].insert(X[i]);
  }

  ll ans = INF;
  repn(i, N) {
    if (U[i] == 0) {

      auto itr = y[1][Y[i]].lower_bound(X[i]);
      if (itr != y[1][Y[i]].begin())
        ans = min(ans, (X[i] - *(--itr)) * 5);

      auto itr2 = xmy[2][X[i] - Y[i]].lower_bound(X[i]);
      if (itr2 != xmy[2][X[i] - Y[i]].begin())
        ans = min(ans, (X[i] - *(--itr2)) * 10);

      auto itr3 = xpy[3][X[i] + Y[i]].lower_bound(X[i]);
      if (itr3 != xpy[3][X[i] + Y[i]].begin())
        ans = min(ans, (X[i] - *(--itr3)) * 10);
    }

    if (U[i] == 1) {
      auto itr = xpy[2][X[i] + Y[i]].lower_bound(X[i]);
      if (itr != xpy[2][X[i] + Y[i]].end())
        ans = min(ans, (*itr - X[i]) * 10);

      auto itr2 = xmy[3][X[i] - Y[i]].lower_bound(X[i]);
      if (itr2 != xmy[3][X[i] - Y[i]].end())
        ans = min(ans, (*itr2 - X[i]) * 10);
    }

    if (U[i] == 2) {
      auto itr = x[3][X[i]].lower_bound(Y[i]);
      if (itr != x[3][X[i]].end())
        ans = min(ans, (*itr - Y[i]) * 5);
    }
  }

  if (ans == INF) {
    cout << "SAFE" << endl;
  } else {
    cout << ans << endl;
  }
}


Error: TLE

Fixed submission:

#include <algorithm>
#include <cmath>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <string>
#define _USE_MATH_DEFINES
#include <complex>
#include <functional>
#include <math.h>
using namespace std;

#define rep(i, x) for (ll i = 0; i < x; i++)
#define repn(i, x) for (ll i = 1; i <= x; i++)

typedef long long ll;
const ll INF = 1e18 + 1e18;
const ll MOD = 1000000007;
const ll MAX = 4000001;
const long double eps = 1E-14;

ll max(ll a, ll b) {
  if (a > b) {
    return a;
  }
  return b;
}

ll min(ll a, ll b) {
  if (a > b) {
    return b;
  }
  return a;
}

ll gcd(ll a, ll b) {
  if (b == 0) {
    return a;
  }
  if (a < b) {
    return gcd(b, a);
  }
  return gcd(b, a % b);
}

ll lcm(ll a, ll b) { return a / gcd(a, b) * b; }

struct edge {
  ll ind;
  ll fr;
  ll to;
  ll d;
};

class mint {
  long long x;

public:
  mint(long long x = 0) : x((x % MOD + MOD) % MOD) {}
  mint operator-() const { return mint(-x); }
  mint &operator+=(const mint &a) {
    if ((x += a.x) >= MOD)
      x -= MOD;
    return *this;
  }
  mint &operator-=(const mint &a) {
    if ((x += MOD - a.x) >= MOD)
      x -= MOD;
    return *this;
  }
  mint &operator*=(const mint &a) {
    (x *= a.x) %= MOD;
    return *this;
  }
  mint operator+(const mint &a) const {
    mint res(*this);
    return res += a;
  }
  mint operator-(const mint &a) const {
    mint res(*this);
    return res -= a;
  }
  mint operator*(const mint &a) const {
    mint res(*this);
    return res *= a;
  }

  mint pow(ll t) const {
    if (!t)
      return 1;
    mint a = pow(t >> 1);
    a *= a;
    if (t & 1)
      a *= *this;
    return a;
  }

  // for prime MOD
  mint inv() const { return pow(MOD - 2); }
  mint &operator/=(const mint &a) { return (*this) *= a.inv(); }
  mint operator/(const mint &a) const {
    mint res(*this);
    return res /= a;
  }

  friend ostream &operator<<(ostream &os, const mint &m) {
    os << m.x;
    return os;
  }
};

mint pw(mint a, ll b) {
  if (b == 0) {
    return 1;
  }
  mint ret = pw(a, b >> 1);
  ret *= ret;
  if (b & 1) {
    ret *= a;
  }
  return ret;
}

typedef vector<ll> vll;
typedef vector<vector<ll>> vvll;
typedef vector<vector<vector<ll>>> vvvll;

typedef vector<mint> vmint;
typedef vector<vector<mint>> vvmint;
typedef vector<vector<vector<mint>>> vvvmint;

//////////////////////////////////////

int main() {
  int N;
  cin >> N;
  vector<int> X(N + 1), Y(N + 1), U(N + 1);
  repn(i, N) {
    cin >> X[i] >> Y[i];
    char c;
    cin >> c;
    if (c == 'L') {
      U[i] = 0;
    }
    if (c == 'R') {
      U[i] = 1;
    }
    if (c == 'U') {
      U[i] = 2;
    }
    if (c == 'D') {
      U[i] = 3;
    }
  }

  vector<map<int, set<int>>> x(4), y(4), xmy(4), xpy(4);

  repn(i, N) {
    x[U[i]][X[i]].insert(Y[i]);
    y[U[i]][Y[i]].insert(X[i]);
    xpy[U[i]][X[i] + Y[i]].insert(X[i]);
    xmy[U[i]][X[i] - Y[i]].insert(X[i]);
  }

  ll ans = INF;
  repn(i, N) {
    if (U[i] == 0) {

      auto v = y[1][Y[i]];
      auto itr = v.lower_bound(X[i]);
      if (itr != v.begin())
        ans = min(ans, (X[i] - *(--itr)) * 5);

      auto v2 = xmy[2][X[i] - Y[i]];
      auto itr2 = v2.lower_bound(X[i]);
      if (itr2 != v2.begin())
        ans = min(ans, (X[i] - *(--itr2)) * 10);

      auto v3 = xpy[3][X[i] + Y[i]];
      auto itr3 = v3.lower_bound(X[i]);
      if (itr3 != v3.begin())
        ans = min(ans, (X[i] - *(--itr3)) * 10);
    }

    if (U[i] == 1) {
      auto v = xpy[2][X[i] + Y[i]];
      auto itr = v.lower_bound(X[i]);
      if (itr != v.end())
        ans = min(ans, (*itr - X[i]) * 10);

      auto v2 = xmy[3][X[i] - Y[i]];
      auto itr2 = v2.lower_bound(X[i]);
      if (itr2 != v2.end())
        ans = min(ans, (*itr2 - X[i]) * 10);
    }

    if (U[i] == 2) {
      auto v = x[3][X[i]];
      auto itr = v.lower_bound(Y[i]);
      if (itr != v.end())
        ans = min(ans, (*itr - Y[i]) * 5);
    }
  }

  if (ans == INF) {
    cout << "SAFE" << endl;
  } else {
    cout << ans << endl;
  }
}