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

#include <bits/stdc++.h>

#define rep(i, n) for (int i = 0; i < int(n); i++)
#define rrep(i, n) for (int i = int(n) - 1; i >= 0; i--)
#define reps(i, n) for (int i = 1; i <= int(n); i++)
#define rreps(i, n) for (int i = int(n); i >= 1; i--)
#define repc(i, n) for (int i = 0; i <= int(n); i++)
#define rrepc(i, n) for (int i = int(n); i >= 0; i--)
#define repi(i, a, b) for (int i = int(a); i < int(b); i++)
#define repic(i, a, b) for (int i = int(a); i <= int(b); i++)
#define all(a) (a).begin(), (a).end()
#define bit32(x) (1 << (x))
#define bit64(x) (1ll << (x))
#define sz(v) ((int)v.size())

using namespace std;

using i64 = long long;
using f80 = long double;
using vi32 = vector<int>;
using vi64 = vector<i64>;
using vf80 = vector<f80>;
using vstr = vector<string>;

void yes() {
  cout << "Yes" << endl;
  exit(0);
}
void no() {
  cout << "No" << endl;
  exit(0);
}
template <typename T>
class pqasc : public priority_queue<T, vector<T>, greater<T>> {};
template <typename T>
class pqdesc : public priority_queue<T, vector<T>, less<T>> {};
template <typename T> void amax(T &x, T y) { x = max(x, y); }
template <typename T> void amin(T &x, T y) { x = min(x, y); }
template <typename T> T exp(T x, i64 n, T e = 1) {
  T r = e;
  while (n > 0) {
    if (n & 1)
      r *= x;
    x *= x;
    n >>= 1;
  }
  return r;
}
template <typename T> istream &operator>>(istream &is, vector<T> &v) {
  for (auto &x : v)
    is >> x;
  return is;
}
template <typename T> ostream &operator<<(ostream &os, vector<T> &v) {
  rep(i, v.size()) {
    if (i)
      os << ' ';
    os << v[i];
  }
  return os;
}
void solve();
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout << fixed << setprecision(16);
  solve();
  return 0;
}

const int INF = 1001001001;
const int dx[] = {1, 0, -1, 0};
const int dy[] = {0, 1, 0, -1};

void solve() {
  int n;
  cin >> n;
  vi32 V(n + 1), W(n + 1);
  reps(i, n) { cin >> V[i] >> W[i]; }
  using T = tuple<int, int>;
  vector<vi32> vans(n + 1);
  auto make = [&](int v) {
    vector<T> st;
    st.emplace_back(0, 0);
    while (v >= 1) {
      if (sz(vans[v])) {
        return make_pair(st, v);
      }
      vector<T> ot;
      rep(i, sz(st)) {
        int weight, value;
        tie(weight, value) = st[i];
        ot.emplace_back(weight, value);
        ot.emplace_back(weight + W[v], value + V[v]);
      }
      swap(st, ot);
      v /= 2;
    }
    return make_pair(st, -1);
  };
  repic(u, exp(2, 9), min(n, exp(2, 10) - 1)) {
    auto st = make(u).first;
    vi32 v(100001);
    rep(i, sz(st)) {
      int weight, value;
      tie(weight, value) = st[i];
      if (weight > 100000)
        continue;
      amax(v[weight], value);
    }
    rep(i, 100000) amax(v[i + 1], v[i]);
    vans[u] = v;
  }
  int q;
  cin >> q;
  rep(qi, q) {
    int v, L;
    cin >> v >> L;
    vector<T> st;
    int u;
    tie(st, u) = make(v);
    int ans = 0;
    if (u == -1) {
      rep(i, sz(st)) {
        int weight, value;
        tie(weight, value) = st[i];
        if (weight <= L)
          amax(ans, value);
      }
    } else {
      rep(i, sz(st)) {
        int weight, value;
        tie(weight, value) = st[i];
        int rest = L - weight;
        if (rest < 0)
          continue;
        amax(ans, value + vans[u][rest]);
      }
    }
    cout << ans << '\\n';
  }
}


Error: TLE

Fixed submission:

#include <bits/stdc++.h>

#define rep(i, n) for (int i = 0; i < int(n); i++)
#define rrep(i, n) for (int i = int(n) - 1; i >= 0; i--)
#define reps(i, n) for (int i = 1; i <= int(n); i++)
#define rreps(i, n) for (int i = int(n); i >= 1; i--)
#define repc(i, n) for (int i = 0; i <= int(n); i++)
#define rrepc(i, n) for (int i = int(n); i >= 0; i--)
#define repi(i, a, b) for (int i = int(a); i < int(b); i++)
#define repic(i, a, b) for (int i = int(a); i <= int(b); i++)
#define all(a) (a).begin(), (a).end()
#define bit32(x) (1 << (x))
#define bit64(x) (1ll << (x))
#define sz(v) ((int)v.size())

using namespace std;

using i64 = long long;
using f80 = long double;
using vi32 = vector<int>;
using vi64 = vector<i64>;
using vf80 = vector<f80>;
using vstr = vector<string>;

void yes() {
  cout << "Yes" << endl;
  exit(0);
}
void no() {
  cout << "No" << endl;
  exit(0);
}
template <typename T>
class pqasc : public priority_queue<T, vector<T>, greater<T>> {};
template <typename T>
class pqdesc : public priority_queue<T, vector<T>, less<T>> {};
template <typename T> void amax(T &x, T y) { x = max(x, y); }
template <typename T> void amin(T &x, T y) { x = min(x, y); }
template <typename T> T exp(T x, i64 n, T e = 1) {
  T r = e;
  while (n > 0) {
    if (n & 1)
      r *= x;
    x *= x;
    n >>= 1;
  }
  return r;
}
template <typename T> istream &operator>>(istream &is, vector<T> &v) {
  for (auto &x : v)
    is >> x;
  return is;
}
template <typename T> ostream &operator<<(ostream &os, vector<T> &v) {
  rep(i, v.size()) {
    if (i)
      os << ' ';
    os << v[i];
  }
  return os;
}
void solve();
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout << fixed << setprecision(16);
  solve();
  return 0;
}

const int INF = 1001001001;
const int dx[] = {1, 0, -1, 0};
const int dy[] = {0, 1, 0, -1};

void solve() {
  int n;
  cin >> n;
  vi32 V(n + 1), W(n + 1);
  reps(i, n) { cin >> V[i] >> W[i]; }
  using T = tuple<int, int>;
  vector<vector<int>> vans(n + 1);
  auto make = [&](int v) {
    vector<T> st;
    st.emplace_back(0, 0);
    while (v >= 1) {
      if (sz(vans[v])) {
        return make_pair(st, v);
      }
      vector<T> ot;
      rep(i, sz(st)) {
        int weight, value;
        tie(weight, value) = st[i];
        ot.emplace_back(weight, value);
        ot.emplace_back(weight + W[v], value + V[v]);
      }
      swap(st, ot);
      v /= 2;
    }
    return make_pair(st, -1);
  };
  if (n >= exp(2, 9)) {
    repic(u, exp(2, 9), min(n, exp(2, 10) - 1)) {
      auto st = make(u).first;
      vi32 v(100001);
      rep(i, sz(st)) {
        int weight, value;
        tie(weight, value) = st[i];
        if (weight > 100000)
          break;
        amax(v[weight], value);
      }
      rep(i, 100000) amax(v[i + 1], v[i]);
    }
  }
  int q;
  cin >> q;
  rep(qi, q) {
    int v, L;
    cin >> v >> L;
    vector<T> st;
    int u;
    tie(st, u) = make(v);
    int ans = 0;
    if (u == -1) {
      rep(i, sz(st)) {
        int weight, value;
        tie(weight, value) = st[i];
        if (weight <= L)
          amax(ans, value);
      }
    } else {
      rep(i, sz(st)) {
        int weight, value;
        tie(weight, value) = st[i];
        int rest = L - weight;
        if (rest < 0)
          continue;
        amax(ans, value + vans[u][rest]);
      }
    }
    cout << ans << '\\n';
  }
}