/* このコード、と~おれ! Be accepted! ∧_∧  (。・ω・。)つ━☆・*。 ⊂   ノ    ・゜+.  しーJ   °。+ *´¨)          .· ´¸.·*´¨) ¸.·*¨)           (¸.·´ (¸.·'* ☆ */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include ////多倍長整数, cpp_intで宣言 //#include //#include //using namespace boost::multiprecision; // #pragma GCC target ("avx2") //#pragma GCC target("arch=skylake-avx512") //#pragma GCC optimiz ("O3") //#pragma GCC target ("sse4") //#pragma GCC optimization ("unroll-loops") //#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native") #define repeat(i, n, m) for(int i = n; i < (m); ++i) #define rep(i, n) for(int i = 0; i < (n); ++i) #define printynl(a) printf(a ? "yes\n" : "no\n") #define printyn(a) printf(a ? "Yes\n" : "No\n") #define printYN(a) printf(a ? "YES\n" : "NO\n") #define printim(a) printf(a ? "possible\n" : "imposible\n") #define printdb(a) printf("%.50lf\n", a) //少数出力 #define printLdb(a) printf("%.50Lf\n", a) //少数出力 #define printdbd(a) printf("%.16lf\n", a) //少数出力(桁少なめ) #define prints(s) printf("%s\n", s.c_str()) //string出力 #define all(x) (x).begin(), (x).end() #define deg_to_rad(deg) (((deg)/360.0L)*2.0L*PI) #define rad_to_deg(rad) (((rad)/2.0L/PI)*360.0L) #define Please return #define AC 0 #define manhattan_dist(a, b, c, d) (abs(a - c) + abs(b - d)) /*(a, b) から (c, d) のマンハッタン距離 */ #define inf numeric_limits::infinity(); #define linf numeric_limits::infinity() using ll = long long; using ull = unsigned long long; constexpr int INF = 1073741823; constexpr int MINF = -1073741823; constexpr ll LINF = ll(4661686018427387903); constexpr ll MOD = 1e9 + 7; constexpr ll mod = 998244353; constexpr long double eps = 1e-6; const long double PI = acosl(-1.0L); using namespace std; void scans(string& str) { char c; str = ""; scanf("%c", &c); if (c == '\n')scanf("%c", &c); while (c != '\n' && c != -1 && c != ' ') { str += c; scanf("%c", &c); } } void scanc(char& str) { char c; scanf("%c", &c); if (c == -1)return; while (c == '\n') { scanf("%c", &c); } str = c; } double acot(double x) { return PI / 2 - atan(x); } ll LSB(ll n) { return (n & (-n)); } template inline T chmin(T& a, const T& b) { if (a > b)a = b; return a; } template inline T chmax(T& a, const T& b) { if (a < b)a = b; return a; } //atcoder library //#include //using namespace atcoder; //random_device seed_gen; //mt19937 engine(seed_gen()); //uniform_distribution dist(-1.0, 1.0); /*-----------------------------------------ここからコード-----------------------------------------*/ /* * @title modint * @docs kyopro/docs/modint.md */ template struct modint { int val; modint() : val(0) {}; modint(ll x) : val(x >= 0 ? x % mod : (mod + x % mod) % mod) {}; modint& operator=(const modint& x) { val = x.val; return *this; } modint& operator+=(const modint& x) { val += x.val; if (val >= mod)val -= mod; return *this; } modint& operator-=(const modint& x) { val += mod - x.val; if (val >= mod)val -= mod; return *this; } modint& operator*=(const modint& x) { val = (int)((ll)val * (ll)x.val % mod); return *this; } modint& operator/=(const modint& x) { int a = x.val, b = mod, u = 1, v = 0, t; while (b > 0) { t = a / b; swap(a -= t * b, b); swap(u -= t * v, v); } *this *= modint(u); return *this; } modint operator++() { val = (val + 1 == mod ? 0 : val + 1); return *this; } modint operator--() { val = (val == 0 ? mod - 1 : val - 1); return *this; } modint operator+(const modint& x) const { return (modint(*this) += x); } modint operator-(const modint& x) const { return (modint(*this) -= x); } modint operator*(const modint& x) const { return (modint(*this) *= x); } modint operator/(const modint& x) const { return (modint(*this) /= x); } bool operator==(const modint& x)const { return (val == x.val); } bool operator!=(const modint& x)const { return (val != x.val); } bool operator<(const modint& x)const { return (val < x.val); } bool operator>(const modint& x)const { return (val > x.val); } modint pow(ll n) { modint ret(1), a(val); while (n > 0) { if (n % 2) ret *= a; a *= a; n /= 2; } return ret; } static int getmod() { return mod; }; }; using ModInt = modint; using Modint = modint; int main() { int n; ll k; scanf("%d%lld", &n, &k); Modint ans = 0, two = 2; rep(i, n) { int a; scanf("%d", &a); ans += a; } ans *= two.pow(k); printf("%d\n", ans.val); Please AC; }