Problem p03112 (C++)

Buggy submission (status: Time Limit Exceeded):
#include <bits/stdc++.h>
#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
using namespace std;
/*----------------------------------ここからマクロ----------------------------------*/
#define all(a) (a).begin(), (a).end()
#define rall(a) (a).rbegin(), (a).rend()
#define vecin(a) rep(i, a.size()) cin >> a[i]
#define overload4(_1, _2, _3, _4, name, ...) name
#define rep1(n) for (int i = 0; i < (int)n; ++i)
#define rep2(i, n) for (int i = 0; i < (int)n; ++i)
#define rep3(i, a, b) for (int i = (int)a; i < (int)b; ++i)
#define rep4(i, a, b, c) for (int i = (int)a; i < (int)b; i += (int)c)
#define rep(...) overload4(__VA_ARGS__, rep4, rep3, rep2, rep1)(__VA_ARGS__)
#ifdef _DEBUG
#define debug1(a) cerr << #a << ": " << a << "\n"
#define debug2(a, b) cerr << #a << ": " << a << ", " << #b << ": " << b << "\n"
#define debug3(a, b, c)                                                        \
  cerr << #a << ": " << a << ", " << #b << ": " << b << ", " << #c << ": "     \
       << c << "\n"
#define debug4(a, b, c, d)                                                     \
  cerr << #a << ": " << a << ", " << #b << ": " << b << ", " << #c << ": "     \
       << c << ", " << #d << ": " << d << "\n"
#define debug(...)                                                             \
  overload4(__VA_ARGS__, debug4, debug3, debug2, debug1)(__VA_ARGS__)
#define vecout(a)                                                              \
  cerr << #a << ": [";                                                         \
  rep(i, a.size()) {                                                           \
    cout << a[i];                                                              \
    cout << (i == a.size() - 1 ? "" : ",");                                    \
  }                                                                            \
  cerr << "]\n"
#else
#define debug(...)
#define vecout(a)
#endif
#define mp make_pair
// #define doset(x) cout << fixed << setprecision(x)
struct doset {
  doset(int n) {
    cout << fixed << setprecision(n);
    cerr << fixed << setprecision(n);
  }
};
struct myset {
  myset() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
  }
};
using ll = long long;
using ld = long double;
using dou = double;
const int inf = 1 << 30;
const ll INF = 1LL << 60;
const ld pi = 3.14159265358;
const ll mod1 = 1000000007LL;
const ll mod2 = 998244353LL;
typedef pair<ll, ll> P;
template <class T, class U> inline bool chmin(T &a, const U &b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T, class U> inline bool chmax(T &a, const U &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T, class U> inline bool change(T &a, U &b) {
  if (a > b) {
    swap(a, b);
    return 1;
  }
  return 0;
}
// nのm乗をMODで割ったあまりO(logm)
ll modpow(ll n, ll m, ll MOD) {
  if (m == 0)
    return 1;
  if (m < 0)
    return -1;
  ll res = 1;
  while (m) {
    if (m & 1)
      res = (res * n) % MOD;
    m >>= 1;
    n *= n;
    n %= MOD;
  }
  return res;
}

ll mypow(ll n, ll m) {
  if (m == 0)
    return 1;
  if (m < 0)
    return -1;
  ll res = 1;
  while (m) {
    if (m & 1)
      res = (res * n);
    m >>= 1;
    n *= n;
  }
  return res;
}

// 素数判定O(sqrt(N))
template <class T> inline bool isp(T n) {
  bool res = true;
  if (n == 1 || n == 0)
    return false;
  else {
    for (ll i = 2; i * i <= n; i++) {
      if (n % i == 0) {
        res = false;
        break;
      }
    }
    return res;
  }
}

template <class T = int> T in() {
  T x;
  cin >> x;
  return x;
}

inline bool Yes(bool b) {
  cout << (b ? "Yes\n" : "No\n");
  return b;
}
inline bool YES(bool b) {
  cout << (b ? "YES\n" : "NO\n");
  return b;
}

/*----------------------------------マクロここまで----------------------------------*/

ll D(vector<ll> V, ll p) { return *(upper_bound(all(V), p) - 1); }
ll U(vector<ll> V, ll p) { return *lower_bound(all(V), p); }

int main() {
  myset m;
  int A, B, Q;
  cin >> A >> B >> Q;
  vector<ll> veca(A + 2), vecb(B + 2), query(Q);
  rep(i, A) cin >> veca[i + 1];
  rep(i, B) cin >> vecb[i + 1];
  rep(i, Q) cin >> query[i];
  veca[0] = -INF;
  veca.back() = INF;
  vecb[0] = -INF;
  vecb.back() = INF;
  rep(i, Q) {
    ll ans = INF, from = query[i], fc, sc, ua = U(veca, from),
       ub = U(vecb, from), da = D(veca, from), db = D(vecb, from);
    // UU
    fc = ua;
    sc = U(vecb, fc);
    if (!(fc == INF || sc == INF))
      chmin(ans, sc - from);
    fc = ub;
    sc = U(veca, fc);
    if (!(fc == INF || sc == INF))
      chmin(ans, sc - from);
    // UD
    fc = ua;
    sc = D(vecb, fc);
    if (!(fc == INF || sc == -INF))
      chmin(ans, fc - from + fc - sc);
    fc = ub;
    sc = D(veca, fc);
    if (!(fc == INF || sc == -INF))
      chmin(ans, fc - from + fc - sc);
    // DU
    fc = da;
    sc = U(vecb, fc);
    if (!(fc == -INF || sc == INF))
      chmin(ans, from - fc + sc - fc);
    fc = db;
    sc = U(veca, fc);
    if (!(fc == -INF || sc == INF))
      chmin(ans, from - fc + sc - fc);
    // DD
    fc = da;
    sc = D(vecb, fc);
    if (!(fc == -INF || sc == -INF))
      chmin(ans, from - sc);
    fc = db;
    sc = D(veca, fc);
    if (!(fc == -INF || sc == -INF))
      chmin(ans, from - sc);
    cout << ans << "\n";
  }
}


Fixed submission:
#include <bits/stdc++.h>
#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
using namespace std;
/*----------------------------------ここからマクロ----------------------------------*/
#define all(a) (a).begin(), (a).end()
#define rall(a) (a).rbegin(), (a).rend()
#define vecin(a) rep(i, a.size()) cin >> a[i]
#define overload4(_1, _2, _3, _4, name, ...) name
#define rep1(n) for (int i = 0; i < (int)n; ++i)
#define rep2(i, n) for (int i = 0; i < (int)n; ++i)
#define rep3(i, a, b) for (int i = (int)a; i < (int)b; ++i)
#define rep4(i, a, b, c) for (int i = (int)a; i < (int)b; i += (int)c)
#define rep(...) overload4(__VA_ARGS__, rep4, rep3, rep2, rep1)(__VA_ARGS__)
#ifdef _DEBUG
#define debug1(a) cerr << #a << ": " << a << "\n"
#define debug2(a, b) cerr << #a << ": " << a << ", " << #b << ": " << b << "\n"
#define debug3(a, b, c)                                                        \
  cerr << #a << ": " << a << ", " << #b << ": " << b << ", " << #c << ": "     \
       << c << "\n"
#define debug4(a, b, c, d)                                                     \
  cerr << #a << ": " << a << ", " << #b << ": " << b << ", " << #c << ": "     \
       << c << ", " << #d << ": " << d << "\n"
#define debug(...)                                                             \
  overload4(__VA_ARGS__, debug4, debug3, debug2, debug1)(__VA_ARGS__)
#define vecout(a)                                                              \
  cerr << #a << ": [";                                                         \
  rep(i, a.size()) {                                                           \
    cout << a[i];                                                              \
    cout << (i == a.size() - 1 ? "" : ",");                                    \
  }                                                                            \
  cerr << "]\n"
#else
#define debug(...)
#define vecout(a)
#endif
#define mp make_pair
// #define doset(x) cout << fixed << setprecision(x)
struct doset {
  doset(int n) {
    cout << fixed << setprecision(n);
    cerr << fixed << setprecision(n);
  }
};
struct myset {
  myset() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
  }
};
using ll = long long;
using ld = long double;
using dou = double;
const int inf = 1 << 30;
const ll INF = 1LL << 60;
const ld pi = 3.14159265358;
const ll mod1 = 1000000007LL;
const ll mod2 = 998244353LL;
typedef pair<ll, ll> P;
template <class T, class U> inline bool chmin(T &a, const U &b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T, class U> inline bool chmax(T &a, const U &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T, class U> inline bool change(T &a, U &b) {
  if (a > b) {
    swap(a, b);
    return 1;
  }
  return 0;
}
// nのm乗をMODで割ったあまりO(logm)
ll modpow(ll n, ll m, ll MOD) {
  if (m == 0)
    return 1;
  if (m < 0)
    return -1;
  ll res = 1;
  while (m) {
    if (m & 1)
      res = (res * n) % MOD;
    m >>= 1;
    n *= n;
    n %= MOD;
  }
  return res;
}

ll mypow(ll n, ll m) {
  if (m == 0)
    return 1;
  if (m < 0)
    return -1;
  ll res = 1;
  while (m) {
    if (m & 1)
      res = (res * n);
    m >>= 1;
    n *= n;
  }
  return res;
}

// 素数判定O(sqrt(N))
template <class T> inline bool isp(T n) {
  bool res = true;
  if (n == 1 || n == 0)
    return false;
  else {
    for (ll i = 2; i * i <= n; i++) {
      if (n % i == 0) {
        res = false;
        break;
      }
    }
    return res;
  }
}

template <class T = int> T in() {
  T x;
  cin >> x;
  return x;
}

inline bool Yes(bool b) {
  cout << (b ? "Yes\n" : "No\n");
  return b;
}
inline bool YES(bool b) {
  cout << (b ? "YES\n" : "NO\n");
  return b;
}

/*----------------------------------マクロここまで----------------------------------*/

ll D(vector<ll> &V, ll p) { return *(upper_bound(all(V), p) - 1); }
ll U(vector<ll> &V, ll p) { return *lower_bound(all(V), p); }

int main() {
  myset m;
  int A, B, Q;
  cin >> A >> B >> Q;
  vector<ll> veca(A + 2), vecb(B + 2), query(Q);
  rep(i, A) cin >> veca[i + 1];
  rep(i, B) cin >> vecb[i + 1];
  rep(i, Q) cin >> query[i];
  veca[0] = -INF;
  veca.back() = INF;
  vecb[0] = -INF;
  vecb.back() = INF;
  rep(i, Q) {
    ll ans = INF, from = query[i], fc, sc, ua = U(veca, from),
       ub = U(vecb, from), da = D(veca, from), db = D(vecb, from);
    // UU
    fc = ua;
    sc = U(vecb, fc);
    if (!(fc == INF || sc == INF))
      chmin(ans, sc - from);
    fc = ub;
    sc = U(veca, fc);
    if (!(fc == INF || sc == INF))
      chmin(ans, sc - from);
    // UD
    fc = ua;
    sc = D(vecb, fc);
    if (!(fc == INF || sc == -INF))
      chmin(ans, fc - from + fc - sc);
    fc = ub;
    sc = D(veca, fc);
    if (!(fc == INF || sc == -INF))
      chmin(ans, fc - from + fc - sc);
    // DU
    fc = da;
    sc = U(vecb, fc);
    if (!(fc == -INF || sc == INF))
      chmin(ans, from - fc + sc - fc);
    fc = db;
    sc = U(veca, fc);
    if (!(fc == -INF || sc == INF))
      chmin(ans, from - fc + sc - fc);
    // DD
    fc = da;
    sc = D(vecb, fc);
    if (!(fc == -INF || sc == -INF))
      chmin(ans, from - sc);
    fc = db;
    sc = D(veca, fc);
    if (!(fc == -INF || sc == -INF))
      chmin(ans, from - sc);
    cout << ans << "\n";
  }
}