Problem p02648 (C++)

Buggy submission (status: Time Limit Exceeded):
#include <bits/stdc++.h>
// ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
// clock_t start=clock();clock_t
// end=clock();cout<<(double)(end-start)/CLOCKS_PER_SEC<<endl;
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef unsigned int ui;
typedef pair<int, int> pii;
typedef pair<pii, int> ppii;
typedef pair<int, pii> pipi;
typedef pair<ll, ll> pll;
typedef pair<pll, ll> ppll;
typedef pair<ll, pll> plpl;
typedef pair<pii, pii> pippi;
typedef tuple<ll, ll, ll> tl;
typedef pair<double, double> pdd;
typedef vector<vector<ll>> mat;
ll mod = 1000000007;
ll mod2 = 998244353;
ll mod3 = 1000003;
ll mod4 = 998244853;
ll mod5 = 1000000009;
ll inf = 1LL << 61;
int iinf = 1 << 30;
double pi = 3.141592653589793238462643383279L;
double eps = 1e-8;
#define rep(i, m, n) for (ll i = m; i < n; i++)
#define rrep(i, n, m) for (ll i = n; i >= m; i--)
#define srep(itr, st) for (auto itr = st.begin(); itr != st.end(); itr++)
#define mrep(itr, mp) for (auto &itr : mp)
#define Max(a, b) a = max(a, b)
#define Min(a, b) a = min(a, b)
// #define endl "\n"
int dh[4] = {1, -1, 0, 0};
int dw[4] = {0, 0, 1, -1};
int ddh[8] = {-1, -1, -1, 0, 0, 1, 1, 1};
int ddw[8] = {-1, 0, 1, -1, 1, -1, 0, 1};
struct custom_hash {
  static uint64_t splitmix64(uint64_t x) {
    // http://xorshift.di.unimi.it/splitmix64.c
    x += 0x9e3779b97f4a7c15;
    x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
    x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
    return x ^ (x >> 31);
  }

  size_t operator()(uint64_t x) const {
    static const uint64_t FIXED_RANDOM =
        chrono::steady_clock::now().time_since_epoch().count();
    return splitmix64(x + FIXED_RANDOM);
  }
};
#define umh unordered_map<int, int, custom_hash>
ll gcd(ll a, ll b) {
  if (a < b)
    swap(a, b);
  if (b == 0)
    return a;
  if (a % b == 0)
    return b;
  return gcd(b, a % b);
}
ll lcm(ll a, ll b) {
  ll c = gcd(a, b);
  return a * b / c;
}
ll Pow(ll n, ll k) {
  if (k < 0)
    return 0;
  ll ret = 1;
  ll now = n;
  while (k > 0) {
    if (k & 1)
      ret *= now;
    now *= now;
    k /= 2;
  }
  return ret;
}
ll beki(ll n, ll k, ll md) {
  ll ret = 1;
  ll now = n;
  now %= md;
  while (k > 0) {
    if (k % 2 == 1) {
      ret *= now;
      ret %= md;
    }
    now *= now;
    now %= md;
    k /= 2;
  }
  return ret;
}
ll gyaku(ll n, ll md) { return beki(n, md - 2, md); }
ll popcount(ll n) {
  ll ret = 0;
  ll u = n;
  while (u > 0) {
    ret += u % 2;
    u /= 2;
  }
  return ret;
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  int n;
  cin >> n;
  ll v[n], w[n];
  rep(i, 0, n) cin >> v[i] >> w[i];
  if (n == 1) {
    ll q;
    cin >> q;
    rep(i, 0, q) {
      ll a, b;
      cin >> a >> b;
      if (b >= w[0])
        cout << v[0] << endl;
      else
        cout << 0 << endl;
    }
    return 0;
  }
  vector<pll> vv[n];
  vv[0].push_back({0, 0});
  vv[1].push_back({0, 0});
  vv[1].push_back({w[0], v[0]});
  vector<pll> t;
  ll jou = pow(n, 0.75);
  rep(i, 2, jou + 1) {
    rep(j, 0, vv[i / 2].size()) {
      pll p = vv[i / 2][j];
      vv[i].push_back(p);
      vv[i].push_back({p.first + w[i - 1], p.second + v[i - 1]});
    }
    sort(vv[i].begin(), vv[i].end());
  }
  ll q;
  cin >> q;
  vector<pll> ww;
  vector<pll> ne;
  rep(i, 0, q) {
    ll now, ma;
    cin >> now >> ma;
    ww.clear();
    ww.push_back({0, 0});
    while (now > jou) {
      ne.clear();
      rep(j, 0, ww.size()) {
        ne.push_back(ww[j]);
        ne.push_back({ww[j].first + w[now - 1], ww[j].second + v[now - 1]});
      }
      swap(ne, ww);
      now /= 2;
    }
    sort(ww.begin(), ww.end(), greater<pll>());
    ll num = 0;
    ll maa = -inf;
    ll ans = -inf;
    rep(j, 0, ww.size()) {
      ll sa = ma - ww[j].first;
      while (num < vv[now].size() && vv[now][num].first <= sa) {
        Max(maa, vv[now][num].second);
        num++;
      }
      Max(ans, ww[j].second + maa);
    }
    cout << ans << endl;
  }
}


Fixed submission:
#include <bits/stdc++.h>
// ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
// clock_t start=clock();clock_t
// end=clock();cout<<(double)(end-start)/CLOCKS_PER_SEC<<endl;
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef unsigned int ui;
typedef pair<int, int> pii;
typedef pair<pii, int> ppii;
typedef pair<int, pii> pipi;
typedef pair<ll, ll> pll;
typedef pair<pll, ll> ppll;
typedef pair<ll, pll> plpl;
typedef pair<pii, pii> pippi;
typedef tuple<ll, ll, ll> tl;
typedef pair<double, double> pdd;
typedef vector<vector<ll>> mat;
ll mod = 1000000007;
ll mod2 = 998244353;
ll mod3 = 1000003;
ll mod4 = 998244853;
ll mod5 = 1000000009;
ll inf = 1LL << 61;
int iinf = 1 << 30;
double pi = 3.141592653589793238462643383279L;
double eps = 1e-8;
#define rep(i, m, n) for (ll i = m; i < n; i++)
#define rrep(i, n, m) for (ll i = n; i >= m; i--)
#define srep(itr, st) for (auto itr = st.begin(); itr != st.end(); itr++)
#define mrep(itr, mp) for (auto &itr : mp)
#define Max(a, b) a = max(a, b)
#define Min(a, b) a = min(a, b)
// #define endl "\n"
int dh[4] = {1, -1, 0, 0};
int dw[4] = {0, 0, 1, -1};
int ddh[8] = {-1, -1, -1, 0, 0, 1, 1, 1};
int ddw[8] = {-1, 0, 1, -1, 1, -1, 0, 1};
struct custom_hash {
  static uint64_t splitmix64(uint64_t x) {
    // http://xorshift.di.unimi.it/splitmix64.c
    x += 0x9e3779b97f4a7c15;
    x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
    x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
    return x ^ (x >> 31);
  }

  size_t operator()(uint64_t x) const {
    static const uint64_t FIXED_RANDOM =
        chrono::steady_clock::now().time_since_epoch().count();
    return splitmix64(x + FIXED_RANDOM);
  }
};
#define umh unordered_map<int, int, custom_hash>
ll gcd(ll a, ll b) {
  if (a < b)
    swap(a, b);
  if (b == 0)
    return a;
  if (a % b == 0)
    return b;
  return gcd(b, a % b);
}
ll lcm(ll a, ll b) {
  ll c = gcd(a, b);
  return a * b / c;
}
ll Pow(ll n, ll k) {
  if (k < 0)
    return 0;
  ll ret = 1;
  ll now = n;
  while (k > 0) {
    if (k & 1)
      ret *= now;
    now *= now;
    k /= 2;
  }
  return ret;
}
ll beki(ll n, ll k, ll md) {
  ll ret = 1;
  ll now = n;
  now %= md;
  while (k > 0) {
    if (k % 2 == 1) {
      ret *= now;
      ret %= md;
    }
    now *= now;
    now %= md;
    k /= 2;
  }
  return ret;
}
ll gyaku(ll n, ll md) { return beki(n, md - 2, md); }
ll popcount(ll n) {
  ll ret = 0;
  ll u = n;
  while (u > 0) {
    ret += u % 2;
    u /= 2;
  }
  return ret;
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  int n;
  cin >> n;
  ll v[n], w[n];
  rep(i, 0, n) cin >> v[i] >> w[i];
  if (n == 1) {
    ll q;
    cin >> q;
    rep(i, 0, q) {
      ll a, b;
      cin >> a >> b;
      if (b >= w[0])
        cout << v[0] << endl;
      else
        cout << 0 << endl;
    }
    return 0;
  }
  vector<pll> vv[n];
  vv[0].push_back({0, 0});
  vv[1].push_back({0, 0});
  vv[1].push_back({w[0], v[0]});
  vector<pll> t;
  ll jou = pow(n, 0.6);
  rep(i, 2, jou + 1) {
    rep(j, 0, vv[i / 2].size()) {
      pll p = vv[i / 2][j];
      vv[i].push_back(p);
      vv[i].push_back({p.first + w[i - 1], p.second + v[i - 1]});
    }
    sort(vv[i].begin(), vv[i].end());
  }
  ll q;
  cin >> q;
  vector<pll> ww;
  vector<pll> ne;
  rep(i, 0, q) {
    ll now, ma;
    cin >> now >> ma;
    ww.clear();
    ww.push_back({0, 0});
    while (now > jou) {
      ne.clear();
      rep(j, 0, ww.size()) {
        ne.push_back(ww[j]);
        ne.push_back({ww[j].first + w[now - 1], ww[j].second + v[now - 1]});
      }
      swap(ne, ww);
      now /= 2;
    }
    sort(ww.begin(), ww.end(), greater<pll>());
    ll num = 0;
    ll maa = -inf;
    ll ans = -inf;
    rep(j, 0, ww.size()) {
      ll sa = ma - ww[j].first;
      while (num < vv[now].size() && vv[now][num].first <= sa) {
        Max(maa, vv[now][num].second);
        num++;
      }
      Max(ans, ww[j].second + maa);
    }
    cout << ans << endl;
  }
}