Problem p02863 (C++)

Buggy submission (status: Runtime Error):
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#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 all(a) (a).begin(), (a).end()
#define bit(k) (1LL << (k))
#define SUM(v) accumulate(all(v), 0LL)

typedef pair<int, int> i_i;
typedef pair<ll, ll> l_l;
template <class T> using vec = vector<T>;
template <class T> using vvec = vector<vec<T>>;
struct fast_ios {
  fast_ios() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(20);
  };
} fast_ios_;

template <class T> inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
template <class T> inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}

#define TOSTRING(x) string(#x)
template <typename T> istream &operator>>(istream &is, vector<T> &vec) {
  for (T &x : vec)
    is >> x;
  return is;
}
template <typename T> ostream &operator<<(ostream &os, const vector<T> &v) {
  os << "[";
  for (auto _ : v)
    os << _ << ", ";
  os << "]";
  return os;
};
template <typename T> ostream &operator<<(ostream &os, set<T> &st) {
  os << "(";
  for (auto _ : st) {
    os << _ << ", ";
  }
  os << ")";
  return os;
}
template <typename T, typename U>
ostream &operator<<(ostream &os, const pair<T, U> &p) {
  os << "{" << p.first << ", " << p.second << "}";
  return os;
}
template <typename T, typename U>
ostream &operator<<(ostream &os, const map<T, U> &mp) {
  os << "[";
  for (auto _ : mp) {
    os << _ << ", ";
  }
  os << "]" << endl;
  return os;
}

#define DUMPOUT cerr
void dump_func() { DUMPOUT << endl; }
template <class Head, class... Tail>
void dump_func(Head &&head, Tail &&...tail) {
  DUMPOUT << head;
  if (sizeof...(Tail) > 0) {
    DUMPOUT << ", ";
  }
  dump_func(std::move(tail)...);
}

#ifdef DEBUG
#define dbg(...) dump_func(__VA_ARGS__)
#define dump(...)                                                              \
  DUMPOUT << string(#__VA_ARGS__) << ": ";                                     \
  dump_func(__VA_ARGS__)
#else
#define dbg(...)
#define dump(...)
#endif

const int INF = (ll)1e9;
const ll INFLL = (ll)1e18 + 1;
const ll MOD = 1000000007;
// const ll MOD = 998244353;
const long double PI = acos(-1.0);

/*
const int dx[8] = {1, 0, -1, 0, 1, -1, -1, 1};
const int dy[8] = {0, 1, 0, -1, 1, 1, -1, -1};
const string dir = "DRUL";
*/

const int MAXT = 3002;
int main() {
  ll N, T;
  cin >> N >> T;
  vector<l_l> AB;
  rep(i, N) {
    ll a, b;
    cin >> a >> b;
    AB.emplace_back(a, b);
  }
  sort(all(AB));
  vector<ll> dp(T + 1, -1);
  dp[0] = 0;
  rep(i, N) {
    auto [a, b] = AB[i];
    vector<ll> dp2(T + 1, -1);
    rep(j, MAXT) chmax(dp2[j], dp[j]);
    rep(j, T) {
      if (dp[j] >= 0)
        chmax(dp2[min(T, j + a)], dp[j] + b);
    }
    swap(dp, dp2);
  }
  cout << *max_element(all(dp)) << endl;
}


Fixed submission:
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#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 all(a) (a).begin(), (a).end()
#define bit(k) (1LL << (k))
#define SUM(v) accumulate(all(v), 0LL)

typedef pair<int, int> i_i;
typedef pair<ll, ll> l_l;
template <class T> using vec = vector<T>;
template <class T> using vvec = vector<vec<T>>;
struct fast_ios {
  fast_ios() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(20);
  };
} fast_ios_;

template <class T> inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
template <class T> inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}

#define TOSTRING(x) string(#x)
template <typename T> istream &operator>>(istream &is, vector<T> &vec) {
  for (T &x : vec)
    is >> x;
  return is;
}
template <typename T> ostream &operator<<(ostream &os, const vector<T> &v) {
  os << "[";
  for (auto _ : v)
    os << _ << ", ";
  os << "]";
  return os;
};
template <typename T> ostream &operator<<(ostream &os, set<T> &st) {
  os << "(";
  for (auto _ : st) {
    os << _ << ", ";
  }
  os << ")";
  return os;
}
template <typename T, typename U>
ostream &operator<<(ostream &os, const pair<T, U> &p) {
  os << "{" << p.first << ", " << p.second << "}";
  return os;
}
template <typename T, typename U>
ostream &operator<<(ostream &os, const map<T, U> &mp) {
  os << "[";
  for (auto _ : mp) {
    os << _ << ", ";
  }
  os << "]" << endl;
  return os;
}

#define DUMPOUT cerr
void dump_func() { DUMPOUT << endl; }
template <class Head, class... Tail>
void dump_func(Head &&head, Tail &&...tail) {
  DUMPOUT << head;
  if (sizeof...(Tail) > 0) {
    DUMPOUT << ", ";
  }
  dump_func(std::move(tail)...);
}

#ifdef DEBUG
#define dbg(...) dump_func(__VA_ARGS__)
#define dump(...)                                                              \
  DUMPOUT << string(#__VA_ARGS__) << ": ";                                     \
  dump_func(__VA_ARGS__)
#else
#define dbg(...)
#define dump(...)
#endif

const int INF = (ll)1e9;
const ll INFLL = (ll)1e18 + 1;
const ll MOD = 1000000007;
// const ll MOD = 998244353;
const long double PI = acos(-1.0);

/*
const int dx[8] = {1, 0, -1, 0, 1, -1, -1, 1};
const int dy[8] = {0, 1, 0, -1, 1, 1, -1, -1};
const string dir = "DRUL";
*/

const int MAXT = 3002;
int main() {
  ll N, T;
  cin >> N >> T;
  vector<l_l> AB;
  rep(i, N) {
    ll a, b;
    cin >> a >> b;
    AB.emplace_back(a, b);
  }
  sort(all(AB));
  vector<ll> dp(T + 1, -1);
  dp[0] = 0;
  rep(i, N) {
    auto [a, b] = AB[i];
    vector<ll> dp2(T + 1, -1);
    rep(j, T + 1) chmax(dp2[j], dp[j]);
    rep(j, T) {
      if (dp[j] >= 0)
        chmax(dp2[min(T, j + a)], dp[j] + b);
    }
    swap(dp, dp2);
  }
  cout << *max_element(all(dp)) << endl;
}