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

#include <bits/stdc++.h>

using ll = long long;
using uint = unsigned int;
using ull = unsigned long long;
using ld = long double;
template <typename T, int n> using arr = T (&)[n];
template <typename T, int n> using c_arr = const T (&)[n];
template <typename T> using max_heap = std::priority_queue<T>;
template <typename T>
using min_heap = std::priority_queue<T, std::vector<T>, std::greater<T>>;
constexpr int popcount(const ull v) { return v ? __builtin_popcountll(v) : 0; }
constexpr int log2p1(const ull v) { return v ? 64 - __builtin_clzll(v) : 0; }
constexpr int lsbp1(const ull v) { return __builtin_ffsll(v); }
constexpr int clog(const ull v) { return v ? log2p1(v - 1) : 0; }
constexpr ull ceil2(const ull v) { return 1ULL << clog(v); }
constexpr ull floor2(const ull v) {
  return v ? (1ULL << (log2p1(v) - 1)) : 0ULL;
}
constexpr bool btest(const ull mask, const int ind) {
  return (mask >> ind) & 1ULL;
}
template <typename T> void bset(T &mask, const int ind) {
  mask |= ((T)1 << ind);
}
template <typename T> void breset(T &mask, const int ind) {
  mask &= ~((T)1 << ind);
}
template <typename T> void bflip(T &mask, const int ind) {
  mask ^= ((T)1 << ind);
}
template <typename T> void bset(T &mask, const int ind, const bool b) {
  (b ? bset(mask, ind) : breset(mask, ind));
}
template <typename T> bool chmin(T &a, const T &b) {
  return (a > b ? a = b, true : false);
}
template <typename T> bool chmax(T &a, const T &b) {
  return (a < b ? a = b, true : false);
}

template <typename T> constexpr T inf_v = std::numeric_limits<T>::max() / 4;
template <typename Real>
constexpr Real pi_v = Real{3.141592653589793238462643383279502884};
constexpr ull TEN(const int n) { return n == 0 ? 1ULL : TEN(n - 1) * 10ULL; }
template <typename F> struct fix : F {
  fix(F &&f) : F{std::forward<F>(f)} {}
  template <typename... Args> auto operator()(Args &&...args) const {
    return F::operator()(*this, std::forward<Args>(args)...);
  }
};
class printer {
public:
  printer(std::ostream &os_ = std::cout) : os{os_} {}
  template <typename T> int operator()(const T &v) { return os << v, 0; }
  template <typename T> int operator()(const std::vector<T> &vs) {
    for (int i = 0; i < (int)vs.size(); i++) {
      os << (i ? " " : ""), this->operator()(vs[i]);
    }
    return 0;
  }
  template <typename T> int operator()(const std::vector<std::vector<T>> &vss) {
    for (int i = 0; i < (int)vss.size(); i++) {
      os << (0 <= i or i + 1 < (int)vss.size() ? "\\n" : ""),
          this->operator()(vss[i]);
    }
    return 0;
  }
  template <typename T, typename... Args>
  int operator()(const T &v, const Args &...args) {
    return this->operator()(v), os << ' ', this->operator()(args...), 0;
  }
  template <typename... Args> int ln(const Args &...args) {
    return this->operator()(args...), os << '\\n', 0;
  }
  template <typename... Args> int el(const Args &...args) {
    return this->operator()(args...), os << std::endl, 0;
  }
  template <typename... Args>
  int fmt(const std::string &s, const Args &...args) {
    return rec(s, 0, args...);
  }

private:
  int rec(const std::string &s, int index) {
    return os << s.substr(index, s.size()), 0;
  }
  template <typename T, typename... Args>
  int rec(const std::string &s, int index, const T &v, const Args &...args) {
    return index == s.size() ? 0
           : s[index] == '%' ? (this->operator()(v), rec(s, index + 1, args...))
                             : (os << s[index], rec(s, index + 1, v, args...));
  }
  std::ostream &os;
};
printer out;

template <typename T, typename F> std::vector<T> generated(const int n, F f) {
  std::vector<T> ans(n);
  return std::generate(ans.begin(), ans.end(), f), ans;
}
std::vector<int> ioted(const int n, const int offset = 0) {
  std::vector<int> ans(n);
  return std::iota(ans.begin(), ans.end(), offset), ans;
}
template <typename Vs> Vs reversed(const Vs &vs) {
  auto ans = vs;
  return std::reverse(ans.begin(), ans.end()), ans;
}
template <typename T, typename F = std::less<T>>
std::vector<T> sorted(const std::vector<T> &vs, F comp = F{}) {
  auto ans = vs;
  return std::sort(ans.begin(), ans.end(), comp), ans;
}
template <typename F>
std::vector<int> sorted_iota(const int n, F comp = F{}, const int offset = 0) {
  return sorted(ioted(n, offset), comp);
}
class scanner {
public:
  scanner(std::istream &is_ = std::cin) : is{is_} {
    is.tie(nullptr), std::ios::sync_with_stdio(false);
  }
  template <typename T> T val() {
    static T v;
    return is >> v, v;
  }
  template <typename T> T val(const T offset) { return val<T>() - offset; }
  template <typename T> std::vector<T> vec(const int n) {
    return generated<T>(n, [&] { return val<T>(); });
  }
  template <typename T> std::vector<T> vec(const int n, const T offset) {
    return generated<T>(n, [&] { return val<T>(offset); });
  }
  template <typename T>
  std::vector<std::vector<T>> vvec(const int n0, const int n1) {
    return generated<std::vector<T>>(n0, [&] { return vec<T>(n1); });
  }
  template <typename T>
  std::vector<std::vector<T>> vvec(const int n0, const int n1, const T offset) {
    return generated<std::vector<T>>(n0, [&] { return vec<T>(n1, offset); });
  }
  template <typename... Args> auto tup() {
    return std::tuple<std::decay_t<Args>...>{val<Args>()...};
  }
  template <typename... Args> auto tup(const Args &...offsets) {
    return std::tuple<std::decay_t<Args>...>{val<Args>(offsets)...};
  }

private:
  std::istream &is;
};
scanner in;
#define SHOW(...) static_cast<void>(0)

template <typename T, typename Int, int n, int i>
auto make_v(typename std::enable_if<(i == n), c_arr<Int, n>>::type,
            const T &v = T{}) {
  return v;
}
template <typename T, typename Int, int n, int i>
auto make_v(typename std::enable_if<(i < n), c_arr<Int, n>>::type szs,
            const T &v = T{}) {
  return std::vector<decltype(make_v<T, Int, n, i + 1>(szs, v))>(
      szs[i], make_v<T, Int, n, i + 1>(szs, v));
}
template <typename T, typename Int, int n>
auto make_v(c_arr<Int, n> szs, const T &t = T{}) {
  return make_v<T, Int, n, 0>(szs, t);
}
int main() {
  constexpr int L = 100000;
  const auto N = in.val<int>();
  std::vector<int> vs(N + 1), ws(N + 1);
  for (int i = 1; i <= N; i++) {
    vs[i] = in.val<int>(), ws[i] = in.val<int>();
  }
  const auto Q = in.val<int>();
  std::vector<std::vector<int>> qss(N + 1);
  std::vector<int> us(Q), ls(Q);
  std::vector<bool> need(N + 1, false);
  for (int i = 0; i < Q; i++) {
    us[i] = in.val<int>(), ls[i] = in.val<int>();
    qss[us[i]].push_back(i);
    for (int n = us[i]; n >= 1; n /= 2) {
      need[n] = true;
    }
  }
  std::vector<int> ans(Q);
  using pii = std::pair<int, int>;
  std::vector<pii> add;
  auto f = fix([&](auto dfs, int s, std::vector<pii> &lc, std::vector<pii> &rc,
                   int left, int right) -> void {
    if (left == right) {
      left++;
      add.clear();
      for (const auto &[w, v] : lc) {
        const int nw = w + ws[s], nv = v + vs[s];
        if (nw <= L) {
          add.push_back({nw, nv});
        } else {
          break;
        }
      }
      const int len = lc.size();
      for (const auto &p : add) {
        lc.push_back(p);
      }
      std::inplace_merge(lc.begin(), lc.begin() + len, lc.end());
      int v = 0;
      for (auto &p : lc) {
        chmax(v, p.second), chmax(p.second, v);
      }
    } else {
      right++;
      add.clear();
      for (const auto &[w, v] : rc) {
        const int nw = w + ws[s], nv = v + vs[s];
        if (nw <= L) {
          add.push_back({nw, nv});
        } else {
          break;
        }
      }
      const int len = rc.size();
      for (const auto &p : add) {
        rc.push_back(p);
      }
      std::inplace_merge(rc.begin(), rc.begin() + len, rc.end());
      int v = 0;
      for (auto &p : rc) {
        chmax(v, p.second), chmax(p.second, v);
      }
    }
    for (const int qi : qss[s]) {
      const int l = ls[qi];
      int max = 0;
      for (const auto &[rw, rv] : rc) {
        if (rw > l) {
          break;
        }
        const int lw = l - rw;
        auto upper = std::lower_bound(lc.begin(), lc.end(), pii{lw + 1, 0});
        upper--;
        chmax(max, rv + upper->second);
      }
      ans[qi] = max;
    }
    const int lto = s * 2, rto = lto + 1;
    auto olc = lc, orc = rc;
    auto oleft = left, oright = right;
    if (lto <= N and need[lto]) {
      dfs(lto, lc, rc, left, right);
    }
    if (rto <= N and need[rto]) {
      dfs(rto, olc, orc, oleft, oright);
    }
  });
  std::vector<pii> lc{{0, 0}}, rc{{0, 0}};
  f(1, lc, rc, 0, 0);
  for (int i = 0; i < Q; i++) {
    out.ln(ans[i]);
  }
  return 0;
}


Error: TLE

Fixed submission:

#include <bits/stdc++.h>

using ll = long long;
using uint = unsigned int;
using ull = unsigned long long;
using ld = long double;
template <typename T, int n> using arr = T (&)[n];
template <typename T, int n> using c_arr = const T (&)[n];
template <typename T> using max_heap = std::priority_queue<T>;
template <typename T>
using min_heap = std::priority_queue<T, std::vector<T>, std::greater<T>>;
constexpr int popcount(const ull v) { return v ? __builtin_popcountll(v) : 0; }
constexpr int log2p1(const ull v) { return v ? 64 - __builtin_clzll(v) : 0; }
constexpr int lsbp1(const ull v) { return __builtin_ffsll(v); }
constexpr int clog(const ull v) { return v ? log2p1(v - 1) : 0; }
constexpr ull ceil2(const ull v) { return 1ULL << clog(v); }
constexpr ull floor2(const ull v) {
  return v ? (1ULL << (log2p1(v) - 1)) : 0ULL;
}
constexpr bool btest(const ull mask, const int ind) {
  return (mask >> ind) & 1ULL;
}
template <typename T> void bset(T &mask, const int ind) {
  mask |= ((T)1 << ind);
}
template <typename T> void breset(T &mask, const int ind) {
  mask &= ~((T)1 << ind);
}
template <typename T> void bflip(T &mask, const int ind) {
  mask ^= ((T)1 << ind);
}
template <typename T> void bset(T &mask, const int ind, const bool b) {
  (b ? bset(mask, ind) : breset(mask, ind));
}
template <typename T> bool chmin(T &a, const T &b) {
  return (a > b ? a = b, true : false);
}
template <typename T> bool chmax(T &a, const T &b) {
  return (a < b ? a = b, true : false);
}

template <typename T> constexpr T inf_v = std::numeric_limits<T>::max() / 4;
template <typename Real>
constexpr Real pi_v = Real{3.141592653589793238462643383279502884};
constexpr ull TEN(const int n) { return n == 0 ? 1ULL : TEN(n - 1) * 10ULL; }
template <typename F> struct fix : F {
  fix(F &&f) : F{std::forward<F>(f)} {}
  template <typename... Args> auto operator()(Args &&...args) const {
    return F::operator()(*this, std::forward<Args>(args)...);
  }
};
class printer {
public:
  printer(std::ostream &os_ = std::cout) : os{os_} {}
  template <typename T> int operator()(const T &v) { return os << v, 0; }
  template <typename T> int operator()(const std::vector<T> &vs) {
    for (int i = 0; i < (int)vs.size(); i++) {
      os << (i ? " " : ""), this->operator()(vs[i]);
    }
    return 0;
  }
  template <typename T> int operator()(const std::vector<std::vector<T>> &vss) {
    for (int i = 0; i < (int)vss.size(); i++) {
      os << (0 <= i or i + 1 < (int)vss.size() ? "\\n" : ""),
          this->operator()(vss[i]);
    }
    return 0;
  }
  template <typename T, typename... Args>
  int operator()(const T &v, const Args &...args) {
    return this->operator()(v), os << ' ', this->operator()(args...), 0;
  }
  template <typename... Args> int ln(const Args &...args) {
    return this->operator()(args...), os << '\\n', 0;
  }
  template <typename... Args> int el(const Args &...args) {
    return this->operator()(args...), os << std::endl, 0;
  }
  template <typename... Args>
  int fmt(const std::string &s, const Args &...args) {
    return rec(s, 0, args...);
  }

private:
  int rec(const std::string &s, int index) {
    return os << s.substr(index, s.size()), 0;
  }
  template <typename T, typename... Args>
  int rec(const std::string &s, int index, const T &v, const Args &...args) {
    return index == s.size() ? 0
           : s[index] == '%' ? (this->operator()(v), rec(s, index + 1, args...))
                             : (os << s[index], rec(s, index + 1, v, args...));
  }
  std::ostream &os;
};
printer out;

template <typename T, typename F> std::vector<T> generated(const int n, F f) {
  std::vector<T> ans(n);
  return std::generate(ans.begin(), ans.end(), f), ans;
}
std::vector<int> ioted(const int n, const int offset = 0) {
  std::vector<int> ans(n);
  return std::iota(ans.begin(), ans.end(), offset), ans;
}
template <typename Vs> Vs reversed(const Vs &vs) {
  auto ans = vs;
  return std::reverse(ans.begin(), ans.end()), ans;
}
template <typename T, typename F = std::less<T>>
std::vector<T> sorted(const std::vector<T> &vs, F comp = F{}) {
  auto ans = vs;
  return std::sort(ans.begin(), ans.end(), comp), ans;
}
template <typename F>
std::vector<int> sorted_iota(const int n, F comp = F{}, const int offset = 0) {
  return sorted(ioted(n, offset), comp);
}
class scanner {
public:
  scanner(std::istream &is_ = std::cin) : is{is_} {
    is.tie(nullptr), std::ios::sync_with_stdio(false);
  }
  template <typename T> T val() {
    static T v;
    return is >> v, v;
  }
  template <typename T> T val(const T offset) { return val<T>() - offset; }
  template <typename T> std::vector<T> vec(const int n) {
    return generated<T>(n, [&] { return val<T>(); });
  }
  template <typename T> std::vector<T> vec(const int n, const T offset) {
    return generated<T>(n, [&] { return val<T>(offset); });
  }
  template <typename T>
  std::vector<std::vector<T>> vvec(const int n0, const int n1) {
    return generated<std::vector<T>>(n0, [&] { return vec<T>(n1); });
  }
  template <typename T>
  std::vector<std::vector<T>> vvec(const int n0, const int n1, const T offset) {
    return generated<std::vector<T>>(n0, [&] { return vec<T>(n1, offset); });
  }
  template <typename... Args> auto tup() {
    return std::tuple<std::decay_t<Args>...>{val<Args>()...};
  }
  template <typename... Args> auto tup(const Args &...offsets) {
    return std::tuple<std::decay_t<Args>...>{val<Args>(offsets)...};
  }

private:
  std::istream &is;
};
scanner in;
#define SHOW(...) static_cast<void>(0)

template <typename T, typename Int, int n, int i>
auto make_v(typename std::enable_if<(i == n), c_arr<Int, n>>::type,
            const T &v = T{}) {
  return v;
}
template <typename T, typename Int, int n, int i>
auto make_v(typename std::enable_if<(i < n), c_arr<Int, n>>::type szs,
            const T &v = T{}) {
  return std::vector<decltype(make_v<T, Int, n, i + 1>(szs, v))>(
      szs[i], make_v<T, Int, n, i + 1>(szs, v));
}
template <typename T, typename Int, int n>
auto make_v(c_arr<Int, n> szs, const T &t = T{}) {
  return make_v<T, Int, n, 0>(szs, t);
}
int main() {
  constexpr int L = 100000;
  const auto N = in.val<int>();
  const int H = 6;
  std::vector<int> vs(std::max(N + 1, 1 << H), 0),
      ws(std::max(N + 1, 1 << H), 0);
  for (int i = 1; i <= N; i++) {
    vs[i] = in.val<int>(), ws[i] = in.val<int>();
  }
  using pii = std::pair<int, int>;
  std::vector<std::vector<pii>> ucandss(1 << H);
  ucandss[0] = {{0, 0}};
  for (int i = 1; i < (1 << H); i++) {
    const int pi = i / 2;
    std::vector<pii> add;
    for (const auto &[w, v] : ucandss[pi]) {
      const int nw = w + ws[i], nv = v + vs[i];
      if (nw > L) {
        break;
      }
      add.push_back({nw, nv});
    }
    std::merge(ucandss[pi].begin(), ucandss[pi].end(), add.begin(), add.end(),
               std::back_inserter(ucandss[i]));
    int v = 0;
    for (auto &p : ucandss[i]) {
      chmax(v, p.second), chmax(p.second, v);
    }
  }
  const auto Q = in.val<int>();
  for (int q = 0; q < Q; q++) {
    const auto [u, l] = in.tup<int, int>();
    std::vector<pii> lcands{{0, 0}};
    int i = u;
    for (; i >= (1 << H); i /= 2) {
      std::vector<pii> add;
      for (const auto &[w, v] : lcands) {
        const int nw = w + ws[i], nv = v + vs[i];
        if (nw > L) {
          break;
        }
        add.push_back({nw, nv});
      }
      const int len = lcands.size();
      for (const auto &p : add) {
        lcands.push_back(p);
      }
      std::inplace_merge(lcands.begin(), lcands.begin() + len, lcands.end());
    }
    int v = 0;
    for (auto &p : lcands) {
      chmax(v, p.second), chmax(p.second, v);
    }
    int max = 0;
    for (const auto &[lw, lv] : lcands) {
      if (lw > l) {
        break;
      }
      const int rw = l - lw;
      auto upp = std::upper_bound(ucandss[i].begin(), ucandss[i].end(),
                                  pii{rw + 1, 0});
      upp--;
      chmax(max, upp->second + lv);
    }
    out.ln(max);
  }
  return 0;
}