Problem p02648 (C++)

Buggy submission (status: Time Limit Exceeded):
#include <algorithm>
#include <bitset>
#include <climits>
#include <cmath>
#include <cstdio>
#include <iomanip>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <unordered_map>
#include <vector>

#define MOD 1000000007
#define MOD2 998244353
#define int long long
#define double long double
#define EPS 1e-9
// #define PI 3.14159265358979

#define rep(i, n) for (int i = 0; i < (int)(n); i++)

using namespace std;

template <typename T> ostream &operator<<(ostream &os, const vector<T> &A) {
  for (int i = 0; i < A.size(); i++)
    os << A[i] << " ";
  os << endl;
  return os;
}
template <> ostream &operator<<(ostream &os, const vector<vector<int>> &A) {
  int N = A.size();
  for (int i = 0; i < N; i++) {
    for (int j = 0; j < A[i].size(); j++)
      os << A[i][j] << " ";
    os << endl;
  }
  return os;
}

typedef pair<int, int> pii;
typedef long long ll;

struct edge {
  int from, to, d, c;
  edge(int _from = 0, int _to = 0, int _d = 0, int _c = 0) {
    from = _from;
    to = _to;
    d = _d;
    c = _c;
  }
  bool operator<(const edge &rhs) const {
    return (d == rhs.d) ? (c < rhs.c) : (d < rhs.d);
  }
};
struct aabb {
  int x1, y1, x2, y2;
  aabb(int x1, int y1, int x2, int y2) : x1(x1), y1(y1), x2(x2), y2(y2) {}
};

typedef vector<edge> edges;
typedef vector<edges> graph;
struct flow {
  int to, cap, rev, cost;
  flow(int to = 0, int cap = 0, int rev = 0, int cost = 0)
      : to(to), cap(cap), rev(rev), cost(cost) {}
};
typedef vector<vector<flow>> flows;

const int di[4] = {0, -1, 0, 1};
const int dj[4] = {-1, 0, 1, 0};
const int ci[5] = {0, 0, -1, 0, 1};
const int cj[5] = {0, -1, 0, 1, 0};
const ll LINF = LLONG_MAX / 2;
const int INF = INT_MAX / 2;
const double PI = acos(-1);

int pow2(int n) { return 1LL << n; }
template <typename T, typename U> bool chmin(T &x, const U &y) {
  if (x > y) {
    x = y;
    return true;
  }
  return false;
}
template <typename T, typename U> bool chmax(T &x, const U &y) {
  if (x < y) {
    x = y;
    return true;
  }
  return false;
}

struct initializer {
  initializer() { cout << fixed << setprecision(20); }
};
initializer _____;

int N, M, K, T, Q, H, W;
signed main() {
  cin >> N;
  vector<int> V(N + 1), W(N + 1);
  rep(i, N) cin >> V[i + 1] >> W[i + 1];
  cin >> Q;
  int MAXLEVEL = 9;
  M = min(N, (1LL << MAXLEVEL) - 1);
  int LMAX = 1e5 + 1;
  // int LMAX = 10;
  vector<vector<int>> dp(M + 1, vector<int>(LMAX, -1));
  dp[0][0] = 0;
  rep(i2, M) {
    int i = i2 + 1;
    rep(j, LMAX) {
      chmax(dp[i][j], dp[i / 2][j]);
      int k = j - W[i];
      if (k >= 0 && dp[i / 2][k] != -1) {
        chmax(dp[i][j], dp[i / 2][k] + V[i]);
      }
    }
  }
  rep(i2, M) {
    int i = i2 + 1;
    rep(j, LMAX - 1) { chmax(dp[i][j + 1], dp[i][j]); }
  }
  // cout << dp;
  while (Q--) {
    int v, L;
    cin >> v >> L;
    if (v <= (1LL << MAXLEVEL) - 1) {
      cout << dp[v][L] << endl;
    } else {
      vector<pii> A;
      while (v >= (1LL << MAXLEVEL)) {
        A.emplace_back(W[v], V[v]);
        v /= 2;
      }
      int ans = 0;
      int X = A.size();
      for (int b = 0; b < (1 << X); b++) {
        int Wtmp = 0, Vtmp = 0;
        rep(i, X) {
          if ((b >> i) & 1) {
            Wtmp += A[i].first;
            Vtmp += A[i].second;
          }
        }
        if (Wtmp <= L) {
          chmax(ans, dp[v][L - Wtmp] + Vtmp);
        }
      }
      cout << ans << endl;
    }
  }
  return 0;
}

Fixed submission:
#include <algorithm>
#include <bitset>
#include <climits>
#include <cmath>
#include <cstdio>
#include <iomanip>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <unordered_map>
#include <vector>

#define MOD 1000000007
#define MOD2 998244353
#define int long long
#define double long double
#define EPS 1e-9
// #define PI 3.14159265358979

#define rep(i, n) for (int i = 0; i < (int)(n); i++)

using namespace std;

template <typename T> ostream &operator<<(ostream &os, const vector<T> &A) {
  for (int i = 0; i < A.size(); i++)
    os << A[i] << " ";
  os << endl;
  return os;
}
template <> ostream &operator<<(ostream &os, const vector<vector<int>> &A) {
  int N = A.size();
  for (int i = 0; i < N; i++) {
    for (int j = 0; j < A[i].size(); j++)
      os << A[i][j] << " ";
    os << endl;
  }
  return os;
}

typedef pair<int, int> pii;
typedef long long ll;

struct edge {
  int from, to, d, c;
  edge(int _from = 0, int _to = 0, int _d = 0, int _c = 0) {
    from = _from;
    to = _to;
    d = _d;
    c = _c;
  }
  bool operator<(const edge &rhs) const {
    return (d == rhs.d) ? (c < rhs.c) : (d < rhs.d);
  }
};
struct aabb {
  int x1, y1, x2, y2;
  aabb(int x1, int y1, int x2, int y2) : x1(x1), y1(y1), x2(x2), y2(y2) {}
};

typedef vector<edge> edges;
typedef vector<edges> graph;
struct flow {
  int to, cap, rev, cost;
  flow(int to = 0, int cap = 0, int rev = 0, int cost = 0)
      : to(to), cap(cap), rev(rev), cost(cost) {}
};
typedef vector<vector<flow>> flows;

const int di[4] = {0, -1, 0, 1};
const int dj[4] = {-1, 0, 1, 0};
const int ci[5] = {0, 0, -1, 0, 1};
const int cj[5] = {0, -1, 0, 1, 0};
const ll LINF = LLONG_MAX / 2;
const int INF = INT_MAX / 2;
const double PI = acos(-1);

int pow2(int n) { return 1LL << n; }
template <typename T, typename U> bool chmin(T &x, const U &y) {
  if (x > y) {
    x = y;
    return true;
  }
  return false;
}
template <typename T, typename U> bool chmax(T &x, const U &y) {
  if (x < y) {
    x = y;
    return true;
  }
  return false;
}

struct initializer {
  initializer() { cout << fixed << setprecision(20); }
};
initializer _____;

int N, M, K, T, Q, H, W;
signed main() {
  cin >> N;
  vector<int> V(N + 1), W(N + 1);
  rep(i, N) cin >> V[i + 1] >> W[i + 1];
  cin >> Q;
  int MAXLEVEL = 10;
  M = min(N, (1LL << MAXLEVEL) - 1);
  int LMAX = 1e5 + 1;
  // int LMAX = 10;
  vector<vector<int>> dp(M + 1, vector<int>(LMAX, -1));
  dp[0][0] = 0;
  rep(i2, M) {
    int i = i2 + 1;
    rep(j, LMAX) {
      chmax(dp[i][j], dp[i / 2][j]);
      int k = j - W[i];
      if (k >= 0 && dp[i / 2][k] != -1) {
        chmax(dp[i][j], dp[i / 2][k] + V[i]);
      }
    }
  }
  rep(i2, M) {
    int i = i2 + 1;
    rep(j, LMAX - 1) { chmax(dp[i][j + 1], dp[i][j]); }
  }
  // cout << dp;
  while (Q--) {
    int v, L;
    cin >> v >> L;
    if (v <= (1LL << MAXLEVEL) - 1) {
      cout << dp[v][L] << endl;
    } else {
      vector<pii> A;
      while (v >= (1LL << MAXLEVEL)) {
        A.emplace_back(W[v], V[v]);
        v /= 2;
      }
      int ans = 0;
      int X = A.size();
      for (int b = 0; b < (1 << X); b++) {
        int Wtmp = 0, Vtmp = 0;
        rep(i, X) {
          if ((b >> i) & 1) {
            Wtmp += A[i].first;
            Vtmp += A[i].second;
          }
        }
        if (Wtmp <= L) {
          chmax(ans, dp[v][L - Wtmp] + Vtmp);
        }
      }
      cout << ans << endl;
    }
  }
  return 0;
}