Problem p02648 (C++)

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

using namespace std;

#define DEBUG(x) cerr << #x << ": " << x << endl;
#define DEBUG_VEC(v)                                                           \
  cerr << #v << ":";                                                           \
  for (int i = 0; i < v.size(); i++)                                           \
    cerr << " " << v[i];                                                       \
  cerr << endl;
#define DEBUG_MAT(v)                                                           \
  cerr << #v << endl;                                                          \
  for (int i = 0; i < v.size(); i++) {                                         \
    for (int j = 0; j < v[i].size(); j++) {                                    \
      cerr << v[i][j] << " ";                                                  \
    }                                                                          \
    cerr << endl;                                                              \
  }
typedef long long ll;
// #define int ll

#define vi vector<int>
#define vl vector<ll>
#define vii vector<vector<int>>
#define vll vector<vector<ll>>
#define vs vector<string>
#define pii pair<int, int>
#define pis pair<int, string>
#define psi pair<string, int>
#define pll pair<ll, ll>
template <class S, class T>
pair<S, T> operator+(const pair<S, T> &s, const pair<S, T> &t) {
  return pair<S, T>(s.first + t.first, s.second + t.second);
}
template <class S, class T>
pair<S, T> operator-(const pair<S, T> &s, const pair<S, T> &t) {
  return pair<S, T>(s.first - t.first, s.second - t.second);
}
template <class S, class T> ostream &operator<<(ostream &os, pair<S, T> p) {
  os << "(" << p.first << ", " << p.second << ")";
  return os;
}
#define X first
#define Y second
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define rep1(i, n) for (int i = 1; i <= (int)(n); i++)
#define rrep(i, n) for (int i = (int)(n)-1; i >= 0; i--)
#define rrep1(i, n) for (int i = (int)(n); i > 0; i--)
#define REP(i, a, b) for (int i = a; i < b; i++)
#define in(x, a, b) (a <= x && x < b)
#define all(c) c.begin(), 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;
}
#define UNIQUE(v) v.erase(std::unique(v.begin(), v.end()), v.end());
const ll inf = 1000000001;
const ll INF = (ll)1e18 + 1;
const long double pi = 3.1415926535897932384626433832795028841971L;
#define Sp(p) cout << setprecision(25) << fixed << p << endl;
// int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
// int dx2[8] = { 1,1,0,-1,-1,-1,0,1 }, dy2[8] = { 0,1,1,1,0,-1,-1,-1 };
vi dx = {1, 0, -1, 0}, dy = {0, 1, 0, -1};
vi dx2 = {1, 1, 0, -1, -1, -1, 0, 1}, dy2 = {0, 1, 1, 1, 0, -1, -1, -1};
#define fio()                                                                  \
  cin.tie(0);                                                                  \
  ios::sync_with_stdio(false);
// const ll MOD = 1000000007;
const ll MOD = 998244353;
// #define mp make_pair
// #define endl '\n'

signed main() {
  // fio();

  int n;
  scanf("%d", &n);

  int depth = 21;
  int mask = 1 << 20;
  while ((mask & n) == 0) {
    depth--;
    mask >>= 1;
  }
  // DEBUG(depth);

  vi v(n), w(n);
  rep(i, n) {
    scanf("%d %d", &v[i], &w[i]);
    // cin >> v[i] >> w[i];
  }

  int half = depth / 2;
  vector<vector<pii>> dp((1 << half) - 1);
  int n1 = dp.size();

  rep(i, n1) {
    if (i == 0) {
      dp[i].push_back(pii(0, 0));
      dp[i].push_back(pii(w[i], v[i]));
      continue;
    }
    int par = (i - 1) / 2;
    for (int j = 0; j < dp[par].size(); j++) {
      pii wv = dp[par][j];
      dp[i].push_back(wv);
      wv.first += w[i];
      wv.second += v[i];
      dp[i].push_back(wv);
    }
    sort(all(dp[i]));
    UNIQUE(dp[i]);
    vector<pii> dp2;
    int ma = -inf;
    rep(j, dp[i].size()) {
      pii wv = dp[i][j];
      if (wv.first >= 100001)
        break;
      if (wv.second <= ma)
        continue;
      while (dp2.size() > 0 and dp2.back().first == wv.first)
        dp2.pop_back();
      dp2.push_back(wv);
      chmax(ma, wv.second);
    }
    swap(dp[i], dp2);
  }

  // vector<vector<pii>> dp2(n - n1);
  // for (int u = n1; u < n; u++) {
  //     int i = u - n1;
  //     int par = (u - 1) / 2;
  //     if (par < n1) {
  //         dp2[i].push_back(pii(0, 0));
  //         dp2[i].push_back(pii(w[u], v[u]));
  //         continue;
  //     }

  //     for (int j = 0; j < dp2[par - n1].size(); j++) {
  //         pii wv = dp2[par - n1][j];
  //         dp2[i].push_back(wv);
  //         wv.first += w[u];
  //         wv.second += v[u];
  //         dp2[i].push_back(wv);
  //     }
  //     sort(all(dp2[i]));
  //     UNIQUE(dp2[i]);
  //     vector<pii> dp3;
  //     int ma = -inf;
  //     rep (j, dp2[i].size()) {
  //         pii wv = dp2[i][j];
  //         if (wv.first >= 100001) break;
  //         if (wv.second <= ma) continue;
  //         while (dp3.size() > 0 and dp3.back().first == wv.first)
  //         dp3.pop_back(); dp3.push_back(wv); chmax(ma, wv.second);
  //     }
  //     swap(dp2[i], dp3);
  // }

  // DEBUG_MAT(dp);
  // DEBUG_MAT(dp2);

  int q;
  scanf("%d", &q);
  // cin >> q;
  while (q--) {
    int u, l;
    scanf("%d %d", &u, &l);
    // cin >> u >> l;
    u--;
    if (n == 1) {
      if (w[u] <= l) {
        cout << v[u] << endl;
      } else {
        cout << 0 << endl;
      }
      continue;
    }

    if (u < dp.size()) {
      auto itr = lower_bound(all(dp[u]), pii(l + 1, -inf));
      itr--;
      cout << itr->second << '\n';
      continue;
    }

    int par = u;
    vector<pii> his;
    while (par >= dp.size()) {
      his.push_back(pii(w[par], v[par]));
      par = (par - 1) / 2;
    }

    // vector<pii> t1 = dp[par], t2 = dp2[u - n1];

    int ans = 0;
    int m = his.size();
    rep(i, 1 << m) {
      pii wv(0, 0);
      rep(j, m) {
        if (i & (1 << j)) {
          wv.first += his[j].first;
          wv.second += his[j].second;
        }
      }
      int giri = l - wv.first;
      if (giri < 0)
        continue;
      auto itr = lower_bound(all(dp[par]), pii(giri + 1, -inf));
      itr--;
      chmax(ans, wv.second + itr->second);
    }
    cout << ans << '\n';
  }
}

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

using namespace std;

#define DEBUG(x) cerr << #x << ": " << x << endl;
#define DEBUG_VEC(v)                                                           \
  cerr << #v << ":";                                                           \
  for (int i = 0; i < v.size(); i++)                                           \
    cerr << " " << v[i];                                                       \
  cerr << endl;
#define DEBUG_MAT(v)                                                           \
  cerr << #v << endl;                                                          \
  for (int i = 0; i < v.size(); i++) {                                         \
    for (int j = 0; j < v[i].size(); j++) {                                    \
      cerr << v[i][j] << " ";                                                  \
    }                                                                          \
    cerr << endl;                                                              \
  }
typedef long long ll;
// #define int ll

#define vi vector<int>
#define vl vector<ll>
#define vii vector<vector<int>>
#define vll vector<vector<ll>>
#define vs vector<string>
#define pii pair<int, int>
#define pis pair<int, string>
#define psi pair<string, int>
#define pll pair<ll, ll>
template <class S, class T>
pair<S, T> operator+(const pair<S, T> &s, const pair<S, T> &t) {
  return pair<S, T>(s.first + t.first, s.second + t.second);
}
template <class S, class T>
pair<S, T> operator-(const pair<S, T> &s, const pair<S, T> &t) {
  return pair<S, T>(s.first - t.first, s.second - t.second);
}
template <class S, class T> ostream &operator<<(ostream &os, pair<S, T> p) {
  os << "(" << p.first << ", " << p.second << ")";
  return os;
}
#define X first
#define Y second
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define rep1(i, n) for (int i = 1; i <= (int)(n); i++)
#define rrep(i, n) for (int i = (int)(n)-1; i >= 0; i--)
#define rrep1(i, n) for (int i = (int)(n); i > 0; i--)
#define REP(i, a, b) for (int i = a; i < b; i++)
#define in(x, a, b) (a <= x && x < b)
#define all(c) c.begin(), 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;
}
#define UNIQUE(v) v.erase(std::unique(v.begin(), v.end()), v.end());
const ll inf = 1000000001;
const ll INF = (ll)1e18 + 1;
const long double pi = 3.1415926535897932384626433832795028841971L;
#define Sp(p) cout << setprecision(25) << fixed << p << endl;
// int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
// int dx2[8] = { 1,1,0,-1,-1,-1,0,1 }, dy2[8] = { 0,1,1,1,0,-1,-1,-1 };
vi dx = {1, 0, -1, 0}, dy = {0, 1, 0, -1};
vi dx2 = {1, 1, 0, -1, -1, -1, 0, 1}, dy2 = {0, 1, 1, 1, 0, -1, -1, -1};
#define fio()                                                                  \
  cin.tie(0);                                                                  \
  ios::sync_with_stdio(false);
// const ll MOD = 1000000007;
const ll MOD = 998244353;
// #define mp make_pair
// #define endl '\n'

signed main() {
  // fio();

  int n;
  scanf("%d", &n);

  int depth = 21;
  int mask = 1 << 20;
  while ((mask & n) == 0) {
    depth--;
    mask >>= 1;
  }
  // DEBUG(depth);

  vi v(n), w(n);
  rep(i, n) {
    scanf("%d %d", &v[i], &w[i]);
    // cin >> v[i] >> w[i];
  }

  int half = depth / 2;
  if (half == 8 or half == 9) {
    half = 11;
  }
  vector<vector<pii>> dp((1 << half) - 1);
  int n1 = dp.size();

  rep(i, n1) {
    if (i == 0) {
      dp[i].push_back(pii(0, 0));
      dp[i].push_back(pii(w[i], v[i]));
      continue;
    }
    int par = (i - 1) / 2;
    for (int j = 0; j < dp[par].size(); j++) {
      pii wv = dp[par][j];
      dp[i].push_back(wv);
      wv.first += w[i];
      wv.second += v[i];
      dp[i].push_back(wv);
    }
    sort(all(dp[i]));
    UNIQUE(dp[i]);
    vector<pii> dp2;
    int ma = -inf;
    rep(j, dp[i].size()) {
      pii wv = dp[i][j];
      if (wv.first >= 100001)
        break;
      if (wv.second <= ma)
        continue;
      while (dp2.size() > 0 and dp2.back().first == wv.first)
        dp2.pop_back();
      dp2.push_back(wv);
      chmax(ma, wv.second);
    }
    swap(dp[i], dp2);
  }

  // vector<vector<pii>> dp2(n - n1);
  // for (int u = n1; u < n; u++) {
  //     int i = u - n1;
  //     int par = (u - 1) / 2;
  //     if (par < n1) {
  //         dp2[i].push_back(pii(0, 0));
  //         dp2[i].push_back(pii(w[u], v[u]));
  //         continue;
  //     }

  //     for (int j = 0; j < dp2[par - n1].size(); j++) {
  //         pii wv = dp2[par - n1][j];
  //         dp2[i].push_back(wv);
  //         wv.first += w[u];
  //         wv.second += v[u];
  //         dp2[i].push_back(wv);
  //     }
  //     sort(all(dp2[i]));
  //     UNIQUE(dp2[i]);
  //     vector<pii> dp3;
  //     int ma = -inf;
  //     rep (j, dp2[i].size()) {
  //         pii wv = dp2[i][j];
  //         if (wv.first >= 100001) break;
  //         if (wv.second <= ma) continue;
  //         while (dp3.size() > 0 and dp3.back().first == wv.first)
  //         dp3.pop_back(); dp3.push_back(wv); chmax(ma, wv.second);
  //     }
  //     swap(dp2[i], dp3);
  // }

  // DEBUG_MAT(dp);
  // DEBUG_MAT(dp2);

  int q;
  scanf("%d", &q);
  // cin >> q;
  while (q--) {
    int u, l;
    scanf("%d %d", &u, &l);
    // cin >> u >> l;
    u--;
    if (n == 1) {
      if (w[u] <= l) {
        cout << v[u] << endl;
      } else {
        cout << 0 << endl;
      }
      continue;
    }

    if (u < dp.size()) {
      auto itr = lower_bound(all(dp[u]), pii(l + 1, -inf));
      itr--;
      cout << itr->second << '\n';
      continue;
    }

    int par = u;
    vector<pii> his;
    while (par >= dp.size()) {
      his.push_back(pii(w[par], v[par]));
      par = (par - 1) / 2;
    }

    // vector<pii> t1 = dp[par], t2 = dp2[u - n1];

    int ans = 0;
    int m = his.size();
    rep(i, 1 << m) {
      pii wv(0, 0);
      rep(j, m) {
        if (i & (1 << j)) {
          wv.first += his[j].first;
          wv.second += his[j].second;
        }
      }
      int giri = l - wv.first;
      if (giri < 0)
        continue;
      auto itr = lower_bound(all(dp[par]), pii(giri + 1, -inf));
      itr--;
      chmax(ans, wv.second + itr->second);
    }
    cout << ans << '\n';
  }
}