Problem p02662 (C++) — buggy submission, verdict: Runtime Error

/**
 *    author:  math2do
 *    created: 01.06.2020 10:21:11
 **/

#include <bits/stdc++.h>

using namespace std;

template <typename T> T power(T a, long long b) {
  T r = 1;
  while (b > 0) {
    if (b & 1) {
      r *= a;
    }
    a *= a;
    b >>= 1;
  }
  return r;
}

template <typename T> T inverse(T a, T m) {
  a %= m;
  if (a < 0) {
    a += m;
  }
  T b = m, u = 0, v = 1;
  while (a) {
    T t = b / a;
    b -= a * t;
    swap(a, b);
    u -= v * t;
    swap(u, v);
  }
  if (u < 0) {
    u += m;
  }
  return u;
}

template <int _P> struct modnum {
  static constexpr int P = _P;

private:
  int v;

public:
  modnum() : v(0) {}
  modnum(long long _v) {
    v = (int)(_v % P);
    if (v < 0) {
      v += P;
    }
  }
  explicit operator int() const { return v; }
  bool operator==(const modnum &o) const { return v == o.v; }
  bool operator!=(const modnum &o) const { return v != o.v; }
  modnum inverse() const { return modnum(::inverse(v, P)); }
  modnum operator-() const { return modnum(v ? P - v : 0); }
  modnum operator+() const { return *this; }
  modnum &operator++() {
    v++;
    if (v == P) {
      v = 0;
    }
    return *this;
  }
  modnum &operator--() {
    if (v == 0) {
      v = P;
    }
    v--;
    return *this;
  }
  modnum operator++(int) {
    modnum r = *this;
    ++*this;
    return r;
  }
  modnum operator--(int) {
    modnum r = *this;
    --*this;
    return r;
  }
  modnum &operator+=(const modnum &o) {
    v += o.v;
    if (v >= P) {
      v -= P;
    }
    return *this;
  }
  modnum operator+(const modnum &o) const { return modnum(*this) += o; }
  modnum &operator-=(const modnum &o) {
    v -= o.v;
    if (v < 0) {
      v += P;
    }
    return *this;
  }
  modnum operator-(const modnum &o) const { return modnum(*this) -= o; }
  modnum &operator*=(const modnum &o) {
    v = (int)((long long)v * o.v % P);
    return *this;
  }
  modnum operator*(const modnum &o) const { return modnum(*this) *= o; }
  modnum &operator/=(const modnum &o) { return *this *= o.inverse(); }
  modnum operator/(const modnum &o) const { return modnum(*this) /= o; }
};

template <int _P> string to_string(const modnum<_P> &n) {
  return to_string((int)n);
}

template <int _P> ostream &operator<<(ostream &out, const modnum<_P> &n) {
  return out << int(n);
}

template <int _P> istream &operator>>(istream &in, modnum<_P> &n) {
  long long _v;
  in >> _v;
  n = modnum<_P>(_v);
  return in;
}

const int mod = (int)(998244353);
using mint = modnum<mod>;

int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  int n, s;
  cin >> n >> s;
  vector<int> arr(n);
  for (int i = 0; i < n; i++) {
    cin >> arr[i];
  }
  sort(arr.begin(), arr.end());
  vector<vector<mint>> dp(n + 1, vector<mint>(s + 1, mint(-1)));
  function<mint(int, int)> get = [&](int i, int rem) -> mint {
    if (rem == 0 && i == n)
      return 1;
    if (i == n)
      return 0;
    if (dp[i][rem] != mint(-1))
      return dp[i][rem];
    mint ans = 0;
    if (arr[i] <= rem) {
      mint ret_b = get(i + 1, rem - arr[i]); // both a and b
      mint ret_a = get(i + 1, rem);          // only a
      mint excl = get(i + 1, rem);           // neither a nor b
      ans += ret_b + ret_a + excl;
    } else {
      mint ret_a = get(i + 1, rem); // only a
      mint excl = get(i + 1, rem);  // neither a nor b
      ans += ret_a + excl;
    }
    return dp[i][rem] = ans;
  };
  mint ans = get(0, s);
  cout << ans << endl;
  return 0;
}


Error: 0

Fixed submission:

/**
 *    author:  math2do
 *    created: 01.06.2020 09:25:18
 **/

#include <bits/stdc++.h>

using namespace std;

template <typename A, typename B> string to_string(pair<A, B> p);

template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p);

template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p);

string to_string(const string &s) { return '"' + s + '"'; }

string to_string(const char *s) { return to_string((string)s); }

string to_string(bool b) { return (b ? "true" : "false"); }

string to_string(const char &ch) { return "'" + string(1, ch) + "'"; }

string to_string(vector<bool> v) {
  bool first = true;
  string res = "{";
  for (int i = 0; i < static_cast<int>(v.size()); i++) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(v[i]);
  }
  res += "}";
  return res;
}

template <size_t N> string to_string(bitset<N> v) {
  string res = "";
  for (size_t i = 0; i < N; i++) {
    res += static_cast<char>('0' + v[i]);
  }
  reverse(res.begin(), res.end());
  return res;
}

template <typename A> string to_string(A v) {
  bool first = true;
  string res = "{";
  for (const auto &x : v) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(x);
  }
  res += "}";
  return res;
}

template <typename A, typename B> string to_string(pair<A, B> p) {
  return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}

template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " +
         to_string(get<2>(p)) + ")";
}

template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " +
         to_string(get<2>(p)) + ", " + to_string(get<3>(p)) + ")";
}

void debug_out() { cerr << endl; }

template <typename Head, typename... Tail> void debug_out(Head H, Tail... T) {
  cerr << " " << to_string(H);
  debug_out(T...);
}

#ifdef LOCAL
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
#define debug(...) 42
#endif

template <typename T> T power(T a, long long b) {
  T r = 1;
  while (b > 0) {
    if (b & 1) {
      r *= a;
    }
    a *= a;
    b >>= 1;
  }
  return r;
}

template <typename T> T inverse(T a, T m) {
  a %= m;
  if (a < 0) {
    a += m;
  }
  T b = m, u = 0, v = 1;
  while (a) {
    T t = b / a;
    b -= a * t;
    swap(a, b);
    u -= v * t;
    swap(u, v);
  }
  if (u < 0) {
    u += m;
  }
  return u;
}

template <int _P> struct modnum {
  static constexpr int P = _P;

private:
  int v;

public:
  modnum() : v(0) {}
  modnum(long long _v) {
    v = (int)(_v % P);
    if (v < 0) {
      v += P;
    }
  }
  explicit operator int() const { return v; }
  bool operator==(const modnum &o) const { return v == o.v; }
  bool operator!=(const modnum &o) const { return v != o.v; }
  modnum inverse() const { return modnum(::inverse(v, P)); }
  modnum operator-() const { return modnum(v ? P - v : 0); }
  modnum operator+() const { return *this; }
  modnum &operator++() {
    v++;
    if (v == P) {
      v = 0;
    }
    return *this;
  }
  modnum &operator--() {
    if (v == 0) {
      v = P;
    }
    v--;
    return *this;
  }
  modnum operator++(int) {
    modnum r = *this;
    ++*this;
    return r;
  }
  modnum operator--(int) {
    modnum r = *this;
    --*this;
    return r;
  }
  modnum &operator+=(const modnum &o) {
    v += o.v;
    if (v >= P) {
      v -= P;
    }
    return *this;
  }
  modnum operator+(const modnum &o) const { return modnum(*this) += o; }
  modnum &operator-=(const modnum &o) {
    v -= o.v;
    if (v < 0) {
      v += P;
    }
    return *this;
  }
  modnum operator-(const modnum &o) const { return modnum(*this) -= o; }
  modnum &operator*=(const modnum &o) {
    v = (int)((long long)v * o.v % P);
    return *this;
  }
  modnum operator*(const modnum &o) const { return modnum(*this) *= o; }
  modnum &operator/=(const modnum &o) { return *this *= o.inverse(); }
  modnum operator/(const modnum &o) const { return modnum(*this) /= o; }
};

template <int _P> string to_string(const modnum<_P> &n) {
  return to_string((int)n);
}

template <int _P> ostream &operator<<(ostream &out, const modnum<_P> &n) {
  return out << int(n);
}

template <int _P> istream &operator>>(istream &in, modnum<_P> &n) {
  long long _v;
  in >> _v;
  n = modnum<_P>(_v);
  return in;
}

const int mod = (int)(998244353);
using mint = modnum<mod>;

const int N = (int)1e2;
int dp[N + 1][N + 1][N + 1];

int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  int n, s;
  cin >> n >> s;
  vector<int> arr(n);
  for (int i = 0; i < n; i++) {
    cin >> arr[i];
  }
  sort(arr.begin(), arr.end());
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < n + 1; j++) {
      for (int k = 0; k < s + 1; k++) {
        dp[i][j][k] = -1;
      }
    }
  }
  function<int(int, int, int)> get = [&](int len, int i, int rem) {
    if (len == 0 && rem == 0)
      return 1;
    if (i == n)
      return 0;

    if (dp[i][len][rem] != -1)
      return dp[i][len][rem];
    int ans = 0;
    if (arr[i] <= rem) {
      int ret = get(len - 1, i + 1, rem - arr[i]);
      ans += ret;
    }
    int ret = get(len, i + 1, rem);
    ans += ret;
    return dp[i][len][rem] = ans;
  };
  vector<int> how(n + 1, 0);
  for (int len = 1; len <= n; len++) {
    how[len] = get(len, 0, s);
  }
  // debug(arr, s);
  // for (int len = 1; len <= n; len++) {
  //   debug(len, how[len]);
  // }
  mint ans = 0;
  for (int len = 1; len <= n; len++) {
    if (how[len] > 0) {
      int rem = n - len;
      ans += (mint)how[len] * power(mint(2), rem);
    }
  }
  cout << ans << endl;
  return 0;
}