Problem p02648 (C++) — buggy submission, verdict: Time Limit Exceeded

// includes
#include <bits/stdc++.h>
using namespace std;

// macros
#define pb emplace_back
#define mk make_pair
#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define rep(i, n) FOR(i, 0, n)
#define rrep(i, n) for (int i = ((int)(n)-1); i >= 0; i--)
#define irep(itr, st) for (auto itr = (st).begin(); itr != (st).end(); ++itr)
#define irrep(itr, st) for (auto itr = (st).rbegin(); itr != (st).rend(); ++itr)
#define whole(x) (x).begin(), (x).end()
#define sz(x) ((int)(x).size())
#define bit(n) (1LL << (n))
#define F first
#define S second
// functions
template <typename T> void unique(T &c) {
  c.erase(std::unique(c.begin(), c.end()), c.end());
}
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 (a > b) {
    a = b;
    return 1;
  }
  return 0;
}
template <typename T> istream &operator>>(istream &is, vector<T> &vec) {
  for (auto &v : vec)
    is >> v;
  return is;
}
template <typename T> ostream &operator<<(ostream &os, const vector<T> &vec) {
  for (int i = 0; i < vec.size(); i++) {
    os << vec[i];
    if (i + 1 != vec.size())
      os << " ";
  }
  return os;
}
template <typename T> ostream &operator<<(ostream &os, const set<T> &st) {
  for (auto itr = st.begin(); itr != st.end(); ++itr) {
    os << *itr;
    auto titr = itr;
    if (++titr != st.end())
      os << " ";
  }
  return os;
}
template <typename T>
ostream &operator<<(ostream &os, const unordered_set<T> &st) {
  for (auto itr = st.begin(); itr != st.end(); ++itr) {
    os << *itr;
    auto titr = itr;
    if (++titr != st.end())
      os << " ";
  }
  return os;
}
template <typename T> ostream &operator<<(ostream &os, const multiset<T> &st) {
  for (auto itr = st.begin(); itr != st.end(); ++itr) {
    os << *itr;
    auto titr = itr;
    if (++titr != st.end())
      os << " ";
  }
  return os;
}
template <typename T>
ostream &operator<<(ostream &os, const unordered_multiset<T> &st) {
  for (auto itr = st.begin(); itr != st.end(); ++itr) {
    os << *itr;
    auto titr = itr;
    if (++titr != st.end())
      os << " ";
  }
  return os;
}
template <typename T1, typename T2>
ostream &operator<<(ostream &os, const pair<T1, T2> &p) {
  os << "(" << p.first << ", " << p.second << ")";
  return os;
}
template <typename T1, typename T2>
ostream &operator<<(ostream &os, const map<T1, T2> &mp) {
  for (auto itr = mp.begin(); itr != mp.end(); ++itr) {
    os << "(" << itr->first << ", " << itr->second << ")";
    auto titr = itr;
    if (++titr != mp.end())
      os << " ";
  }
  return os;
}
template <typename T1, typename T2>
ostream &operator<<(ostream &os, const unordered_map<T1, T2> &mp) {
  for (auto itr = mp.begin(); itr != mp.end(); ++itr) {
    os << "(" << itr->first << ", " << itr->second << ")";
    auto titr = itr;
    if (++titr != mp.end())
      os << " ";
  }
  return os;
}
//  types
using ll = long long int;
using P = pair<int, int>;
// constants
const int inf = 1e9;
const ll linf = 1LL << 60;
const double EPS = 1e-10;
const int mod = 1000000007;
const int dx[4] = {-1, 0, 1, 0};
const int dy[4] = {0, -1, 0, 1};
// io
struct fast_io {
  fast_io() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout << fixed << setprecision(20);
  }
} fast_io_;

ll v[300010], w[300010];
int x[100010];
ll la[100010];
const int b = 100001;
vector<int> ver;
map<int, ll> mp[1 << 10];
const int k = 9;

void dfs(int it) {
  ver.pb(it);
  if (sz(ver) == k) {
    rep(i, 1 << sz(ver)) {
      ll sumw = 0;
      ll sumv = 0;
      rep(j, sz(ver)) {
        if ((i >> j) & 1) {
          sumw += w[ver[j]];
          sumv += v[ver[j]];
        }
        if (sumw > b)
          break;
      }
      if (sumw <= b) {
        chmax(mp[it][sumw], sumv);
      }
    }
    irep(itr, mp[it]) {
      auto titr = itr;
      if (itr != mp[it].begin()) {
        titr--;
        chmax(itr->second, titr->second);
      }
    }
  } else {
    dfs(2 * it + 1);
    dfs(2 * it + 2);
  }
  ver.pop_back();
}
ll sumw[1 << 9], sumv[1 << 9];
int att[1 << 9];

int main(int argc, char const *argv[]) {
  int n;
  cin >> n;
  rep(i, n) cin >> v[i] >> w[i];
  int q;
  cin >> q;
  rep(i, q) {
    cin >> x[i] >> la[i];
    x[i]--;
  }
  dfs(0);
  for (int i = 1; i < (1 << k); i++) {
    int t = i;
    while (true) {
      if (t & 1)
        break;
      t /= 2;
      att[i]++;
    }
  }
  rep(it, q) {
    vector<int> vers;
    int lt = x[it];
    while (true) {
      vers.pb(lt);
      if (lt == 0)
        break;
      lt = (lt - 1) / 2;
    }
    ll res = 0;
    if (sz(vers) < k) {
      rep(i, 1 << sz(vers)) {
        sumw[i] = 0;
        sumv[i] = 0;
        if (i > 0) {
          int lowe = att[i];
          sumw[i] = sumw[i ^ (1 << lowe)] + w[vers[lowe]];
          sumv[i] = sumv[i ^ (1 << lowe)] + v[vers[lowe]];
        }
        if (sumw[i] <= la[it]) {
          chmax(res, sumv[i]);
        }
      }
    } else {
      reverse(whole(vers));
      int r = vers[8];
      rep(i, 1 << (sz(vers) - k)) {
        sumw[i] = 0;
        sumv[i] = 0;
        if (i > 0) {
          int lowe = att[i];
          sumw[i] = sumw[i ^ (1 << lowe)] + w[vers[k + lowe]];
          sumv[i] = sumv[i ^ (1 << lowe)] + v[vers[k + lowe]];
        }
        if (sumw[i] <= la[it]) {
          auto itr = mp[r].upper_bound(la[it] - sumw[i]);
          if (itr != mp[r].begin()) {
            itr--;
            chmax(res, sumv[i] + itr->second);
          }
        }
      }
    }
    cout << res << endl;
  }
  return 0;
}


Error: TLE

Fixed submission:

// includes
#include <bits/stdc++.h>
using namespace std;

// macros
#define pb emplace_back
#define mk make_pair
#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define rep(i, n) FOR(i, 0, n)
#define rrep(i, n) for (int i = ((int)(n)-1); i >= 0; i--)
#define irep(itr, st) for (auto itr = (st).begin(); itr != (st).end(); ++itr)
#define irrep(itr, st) for (auto itr = (st).rbegin(); itr != (st).rend(); ++itr)
#define whole(x) (x).begin(), (x).end()
#define sz(x) ((int)(x).size())
#define bit(n) (1LL << (n))
#define F first
#define S second
// functions
template <typename T> void unique(T &c) {
  c.erase(std::unique(c.begin(), c.end()), c.end());
}
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 (a > b) {
    a = b;
    return 1;
  }
  return 0;
}
template <typename T> istream &operator>>(istream &is, vector<T> &vec) {
  for (auto &v : vec)
    is >> v;
  return is;
}
template <typename T> ostream &operator<<(ostream &os, const vector<T> &vec) {
  for (int i = 0; i < vec.size(); i++) {
    os << vec[i];
    if (i + 1 != vec.size())
      os << " ";
  }
  return os;
}
template <typename T> ostream &operator<<(ostream &os, const set<T> &st) {
  for (auto itr = st.begin(); itr != st.end(); ++itr) {
    os << *itr;
    auto titr = itr;
    if (++titr != st.end())
      os << " ";
  }
  return os;
}
template <typename T>
ostream &operator<<(ostream &os, const unordered_set<T> &st) {
  for (auto itr = st.begin(); itr != st.end(); ++itr) {
    os << *itr;
    auto titr = itr;
    if (++titr != st.end())
      os << " ";
  }
  return os;
}
template <typename T> ostream &operator<<(ostream &os, const multiset<T> &st) {
  for (auto itr = st.begin(); itr != st.end(); ++itr) {
    os << *itr;
    auto titr = itr;
    if (++titr != st.end())
      os << " ";
  }
  return os;
}
template <typename T>
ostream &operator<<(ostream &os, const unordered_multiset<T> &st) {
  for (auto itr = st.begin(); itr != st.end(); ++itr) {
    os << *itr;
    auto titr = itr;
    if (++titr != st.end())
      os << " ";
  }
  return os;
}
template <typename T1, typename T2>
ostream &operator<<(ostream &os, const pair<T1, T2> &p) {
  os << "(" << p.first << ", " << p.second << ")";
  return os;
}
template <typename T1, typename T2>
ostream &operator<<(ostream &os, const map<T1, T2> &mp) {
  for (auto itr = mp.begin(); itr != mp.end(); ++itr) {
    os << "(" << itr->first << ", " << itr->second << ")";
    auto titr = itr;
    if (++titr != mp.end())
      os << " ";
  }
  return os;
}
template <typename T1, typename T2>
ostream &operator<<(ostream &os, const unordered_map<T1, T2> &mp) {
  for (auto itr = mp.begin(); itr != mp.end(); ++itr) {
    os << "(" << itr->first << ", " << itr->second << ")";
    auto titr = itr;
    if (++titr != mp.end())
      os << " ";
  }
  return os;
}
//  types
using ll = long long int;
using P = pair<int, int>;
// constants
const int inf = 1e9;
const ll linf = 1LL << 60;
const double EPS = 1e-10;
const int mod = 1000000007;
const int dx[4] = {-1, 0, 1, 0};
const int dy[4] = {0, -1, 0, 1};
// io
struct fast_io {
  fast_io() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout << fixed << setprecision(20);
  }
} fast_io_;

ll v[300010], w[300010];
int x[100010];
ll la[100010];
const int b = 100001;
vector<int> ver;
map<int, ll> mp[1 << 10];
const int k = 9;

void dfs(int it) {
  ver.pb(it);
  if (sz(ver) == k) {
    rep(i, 1 << sz(ver)) {
      ll sumw = 0;
      ll sumv = 0;
      rep(j, sz(ver)) {
        if ((i >> j) & 1) {
          sumw += w[ver[j]];
          sumv += v[ver[j]];
        }
        if (sumw > b)
          break;
      }
      if (sumw <= b) {
        chmax(mp[it][sumw], sumv);
      }
    }
    irep(itr, mp[it]) {
      auto titr = itr;
      if (itr != mp[it].begin()) {
        titr--;
        chmax(itr->second, titr->second);
      }
    }
  } else {
    dfs(2 * it + 1);
    dfs(2 * it + 2);
  }
  ver.pop_back();
}

int main(int argc, char const *argv[]) {
  int n;
  cin >> n;
  rep(i, n) cin >> v[i] >> w[i];
  int q;
  cin >> q;
  rep(i, q) {
    cin >> x[i] >> la[i];
    x[i]--;
  }
  dfs(0);
  rep(it, q) {
    vector<int> vers;
    int lt = x[it];
    while (true) {
      vers.pb(lt);
      if (lt == 0)
        break;
      lt = (lt - 1) / 2;
    }
    ll res = 0;
    if (sz(vers) < k) {
      rep(i, 1 << sz(vers)) {
        ll sumw = 0;
        ll sumv = 0;
        rep(j, sz(vers)) {
          if ((i >> j) & 1) {
            sumw += w[vers[j]];
            sumv += v[vers[j]];
          }
          if (sumw > la[it])
            break;
        }
        if (sumw <= la[it]) {
          chmax(res, sumv);
        }
      }
    } else {
      reverse(whole(vers));
      int r = vers[8];
      rep(i, 1 << (sz(vers) - k)) {
        ll sumw = 0;
        ll sumv = 0;
        rep(j, sz(vers) - k) {
          if ((i >> j) & 1) {
            sumw += w[vers[k + j]];
            sumv += v[vers[k + j]];
          }
          if (sumw > la[it])
            break;
        }
        if (sumw <= la[it]) {
          auto itr = mp[r].upper_bound(la[it] - sumw);
          if (itr != mp[r].begin()) {
            itr--;
            chmax(res, sumv + itr->second);
          }
        }
      }
    }
    cout << res << endl;
  }
  return 0;
}