Language: C++

#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <stack>
#include <queue>
#include <cmath>
#include <tuple>
#include <cstdio>
#include <bitset>
#include <sstream>
#include <iterator>
#include <numeric>
#include <map>
#include <cstring>
#include <set>
#include <functional>
#include <iomanip>

using namespace std;

#define DEBUG_ //!!$BDs=P;~$K%3%a%s%H%"%&%H(B!!
#ifdef DEBUG_
#define dump(x)  cerr << #x << " = " << (x) << endl;
#else
#define dump(x)  ;
#endif

#define equals(a,b) (fabs((a)-(b)) < EPS)
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n)  FOR(i,0,n)
#define SZ(x) ((int)(x).size())
#define pb push_back
#define eb emplace_back

//#define int long long

typedef long long LL;
typedef vector<int> VI;
typedef vector<LL> VL;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef pair<LL, LL> PLL;

template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }

    template <typename T>
std::string printVector(const std::vector<T> &data)
{
    std::stringstream ss;
    std::ostream_iterator<T> out_it(ss, ", ");
    ss << "[";
    std::copy(data.begin(), data.end() - 1, out_it);
    ss << data.back() << "]";
    return ss.str();
}

template <typename T>
void print_array(const T &ary, int size){
    REP(i,size){
        cout << ary[i] << " ";
    }
    cout << endl;
}

const int mod = 998244353;
const LL LINF = 1001002003004005006ll;
const int INF = 1001001001;
const double EPS = (1e-10);
const long double PI = 3.14159265358979323846264338327950288419716939937510582097494459230781640628620899;
int dx[] = {0,0,-1,1};
int dy[] = {-1,1,0,0};


struct mint {
    LL x; // typedef long long LL;
    mint(LL x=0):x( x >= 0 ? x%mod : x%mod+mod){}
    mint& operator+=(const mint a) {
        if ((x += a.x) >= mod) x -= mod;
        return *this;
    }
    mint& operator-=(const mint a) {
        if ((x += mod-a.x) >= mod) x -= mod;
        return *this;
    }
    mint& operator*=(const mint a) {
        (x *= a.x) %= mod;
        return *this;
    }
    mint operator+(const mint a) const {
        mint res(*this);
        return res+=a;
    }
    mint operator-(const mint a) const {
        mint res(*this);
        return res-=a;
    }
    mint operator*(const mint a) const {
        mint res(*this);
        return res*=a;
    }
    mint pow(LL t) const {
        if (!t) return 1;
        mint a = pow(t>>1);
        a *= a;
        if (t&1) a *= *this;
        return a;
    }

    // for prime mod
    mint inv() const {
        return pow(mod-2);
    }
    mint& operator/=(const mint a) {
        return (*this) *= a.inv();
    }
    mint operator/(const mint a) const {
        mint res(*this);
        return res/=a;
    }
};

signed main(int argc, char const *argv[])
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    cout << setprecision(12);
    int N,S; cin >> N >> S;
    VI A(N);
    REP(i,N) cin >> A[i];
    vector<mint> dp(3010);
    mint base = mint(2).pow(N-1);
    mint tow_inv = mint(2).inv();

    REP(i,N){
        for(int j = 3005; j >= 0; j--){
            if(j-A[i] >= 0) dp[j] += dp[j-A[i]] * two_inv;
        }

        dp[A[i]] += base;
    }
    cout << dp[S].x << endl;


}


Compiler output:
a.cc: In function 'int main(int, const char**)':
a.cc:139:51: error: 'two_inv' was not declared in this scope; did you mean 'tow_inv'?
  139 |             if(j-A[i] >= 0) dp[j] += dp[j-A[i]] * two_inv;
      |                                                   ^~~~~~~
      |                                                   tow_inv