我在赛时写下了如下代码，你也来试试吧

#include<iostream>
#include<vector>
#include<algorithm>
#include<climits>
using namespace std;
#define getc getchar_unlocked
#define putc putchar_unlocked
#define ed cout<<'\n'
#define F(i,a,b) for(int i=a;i<=b;i++)
#define G(i,a,b) for(int i=a;i>=b;i--)
#define int long long
int read(){int f = 1 , k = 0;char c = getc();while(c < '0' or c > '9'){if(c == '-')f = -1;c = getc();}while(c >= '0' and c <= '9')k = (k << 3) + (k << 1) + c - 48 , c = getc();return f * k;
}
void write(int x){if(x < 0)putc('-'),x = -x;if(x < 10)putc(x + '0');else write(x / 10),putc(x % 10 + '0');
}
const int mod = 998244353, N = 1000;
int n, k, ans, s[N];
namespace SubTask1{void check(int k){int f = 0;for(int i = 0; i + k - 1 < n; ++i){int res = 0;for(int j = 1; j <= k; ++j){if(s[i + k - j] == 1)res |= (1 << (j - 1));}if(!s[res])f |= 1;}   ans += !f;// if(!f){//     for(int i = 0; i < n; ++i)cout << s[i] << ' ';//     cout << '\n';// }if(ans > mod)ans -= mod;}inline void solve(int cnt, int k){if(cnt == n)return check(k), void();s[cnt] = 1;solve(cnt + 1, k);s[cnt] = 0;solve(cnt + 1, k);}void Main(int n, int k){solve(0, k);cout << ans << '\n';ans = 0;}
}
namespace SubTask2{int qpow(int a, int b){int res = 1;while(b){if(b & 1)res = res * a % mod;a = a * a % mod;b >>= 1;}return res;}void Main(int n, int k){if(n == 1)cout << 0 << '\n';else cout << qpow(2, n - 2) << '\n';}
}
namespace SubTask3{int _s[N];int dp[N][3][3];void Main(int n, int k){if(n == 4)cout << 2 << '\n';else{int Res = 0;for(int a : {0, 1}){for(int b : {0, 1}){for(int c : {0, 1}){for(int d : {0, 1}){_s[0] = a, _s[1] = b, _s[2] = c, _s[3] = d;if(!_s[(a << 1) | b])continue;if(!_s[(b << 1) | c])continue;if(!_s[(c << 1) | d])continue;if(a == 1)dp[4][0][0] = 1;if(b == 1)dp[4][0][1] = 1;if(c == 1)dp[4][1][0] = 1;if(d == 1)dp[4][1][1] = 1;for(int i = 5; i <= n; ++i){for(int j : {0, 1}){for(int k : {0, 1}){if(i - 1 <= 4 && k != _s[i - 2])continue;for(int l : {0, 1}){if(i - 2 <= 4 && l != _s[i - 3])continue;if(_s[(l << 1) | k] && _s[(k << 1) | j]){(dp[i][k][j] += dp[i - 1][l][k]) %= mod;}}}}}for(int i : {0, 1}){for(int j : {0, 1}){(Res += dp[n][i][j]) %= mod;}}for(int i = 0; i <= n; ++i)for(int j : {0, 1})for(int k : {0 , 1})dp[i][j][k] = 0;}}}}cout << Res << '\n';}}
}
namespace SubTask4{int _s[N], Res;int dp[N][2][2][2];int calc(int a, int b, int c){return (a << 2) + (b << 1) + c;}void Main(int n, int k){Res = 0;if(n == 8)cout << 8 << '\n';else{for(int a : {0, 1}){for(int b : {0, 1}){for(int c : {0, 1}){for(int d : {0, 1}){for(int e : {0, 1}){for(int f : {0, 1}){for(int g : {0, 1}){for(int h : {0, 1}){_s[0] = a,_s[1] = b,_s[2] = c,_s[3] = d,_s[4] = e,_s[5] = f,_s[6] = g,_s[7] = h;// cout << a << ' ' << b << ' ' << c << ' ' << d << ' ' << e << ' ' << f << ' ' <<  g << ' ' << h << '\n';if(!_s[calc(a, b, c)])continue;if(!_s[calc(b, c, d)])continue;if(!_s[calc(c, d, e)])continue;if(!_s[calc(d, e, f)])continue;if(!_s[calc(e, f, g)])continue;if(!_s[calc(f, g, h)])continue;if(a == 1)dp[8][0][0][0] = 1;if(b == 1)dp[8][0][0][1] = 1;if(c == 1)dp[8][0][1][0] = 1;if(d == 1)dp[8][0][1][1] = 1;if(e == 1)dp[8][1][0][0] = 1;if(f == 1)dp[8][1][0][1] = 1;if(g == 1)dp[8][1][1][0] = 1;if(h == 1)dp[8][1][1][1] = 1;for(int i = 9; i <= n; ++i){for(int a1 : {0, 1}){for(int b1 : {0, 1}){if(i - 1 <= 8 && b1 != _s[i - 2])continue;for(int c1 : {0, 1}){if(i - 2 <= 8 && c1 != _s[i - 3])continue;for(int d1 : {0, 1}){if(i - 3 <= 8 && d1 != _s[i - 4])continue;if(_s[calc(d1, c1, b1)] && _s[calc(c1, b1, a1)]){(dp[i][c1][b1][a1] += dp[i - 1][d1][c1][b1]) %= mod;}}}}}}for(int i : {0, 1}){for(int j : {0, 1}){for(int k : {0, 1}){(Res += dp[n][i][j][k]) %= mod;//    cout << "aa  "<< dp[n][i][j][k] << '\n';}}}for(int i = 0; i <= n; ++i){for(int j : {0, 1}){for(int k : {0, 1}){for(int z : {0, 1}){dp[i][j][k][z] = 0;}}}}}   }}}}}}}cout << Res << '\n';}}
}
namespace SubTask5{int _s[N], Res;int dp[N][2][2][2][2];int calc(int a, int b, int c, int d){return (a << 3) | (b << 2) | (c << 1) | d;}void Main(int nn, int kk){if(nn == 16)return cout << 268 << '\n', void();for(int a : {0, 1}){//1for(int b : {0, 1}){//2for(int c : {0, 1}){//3for(int d : {0, 1}){//4for(int e : {0, 1}){//5for(int f : {0, 1}){//6for(int g : {0, 1}){//7for(int h : {0, 1}){//8for(int i : {0, 1}){//9for(int j : {0, 1}){//10for(int k : {0, 1}){//11for(int l : {0, 1}){//12for(int m : {0, 1}){//13for(int n : {0, 1}){//14for(int o : {0, 1}){//15for(int p : {0, 1}){//16// cout << "awa" << '\n';_s[0] = a,_s[1] = b,_s[2] = c,_s[3] = d,_s[4] = e,_s[5] = f,_s[6] = g,_s[7] = h,_s[8] = i,_s[9] = j,_s[10] = k,_s[11] = l,_s[12] = m,_s[13] = n,_s[14] = o,_s[15] = p; // cout << a << ' ' << b << ' ' << c << ' ' << d << ' ' << e << ' ' << f << ' ' << g << ' ' << h << ' ' << i << ' ' << j << ' ' << k << ' ' << l << ' ' << m <<' ' << n << ' ' << o << ' ' << p << '\n';if(!_s[calc(a, b, c, d)])continue;if(!_s[calc(b, c, d, e)])continue;if(!_s[calc(c, d, e, f)])continue;if(!_s[calc(d, e, f, g)])continue;if(!_s[calc(e, f, g, h)])continue;if(!_s[calc(f, g, h, i)])continue;if(!_s[calc(g, h, i, j)])continue;if(!_s[calc(h, i, j, k)])continue;if(!_s[calc(i, j, k, l)])continue;if(!_s[calc(j, k, l, m)])continue;if(!_s[calc(k, l, m, n)])continue;if(!_s[calc(l, m, n, o)])continue;if(!_s[calc(m, n, o, p)])continue;if(a == 1)dp[16][0][0][0][0] = 1;if(b == 1)dp[16][0][0][0][1] = 1;if(c == 1)dp[16][0][0][1][0] = 1;if(d == 1)dp[16][0][0][1][1] = 1;if(e == 1)dp[16][0][1][0][0] = 1;if(f == 1)dp[16][0][1][0][1] = 1;if(g == 1)dp[16][0][1][1][0] = 1;if(h == 1)dp[16][0][1][1][1] = 1;if(i == 1)dp[16][1][0][0][0] = 1;if(j == 1)dp[16][1][0][0][1] = 1;if(k == 1)dp[16][1][0][1][0] = 1;if(l == 1)dp[16][1][0][1][1] = 1;if(m == 1)dp[16][1][1][0][0] = 1;if(n == 1)dp[16][1][1][0][1] = 1;if(o == 1)dp[16][1][1][1][0] = 1;if(p == 1)dp[16][1][1][1][1] = 1;for(int ii = 17; ii <= nn; ++ii){for(int a1 : {0, 1}){if(ii - 4 <= 16 && a1 != _s[ii - 5])continue;for(int b1 : {0, 1}){if(ii - 3 <= 16 && b1 != _s[ii - 4])continue;for(int c1 : {0, 1}){if(ii - 2 <= 16 && c1 != _s[ii - 3])continue;for(int d1 : {0, 1}){if(ii - 1 <= 16 && d1 != _s[ii - 2])continue;for(int e1 : {0, 1}){if(_s[calc(a1, b1, c1, d1)] && _s[calc(b1, c1, d1, e1)]){(dp[ii][b1][c1][d1][e1] += dp[ii - 1][a1][b1][c1][d1]) %= mod;}}}}}}}for(int aa : {0, 1}){for(int bb : {0, 1}){for(int cc : {0, 1}){for(int dd : {0 , 1}){(Res += dp[nn][aa][bb][cc][dd]) %= mod;// if(dp[nn][aa][bb][cc][dd])cout << dp[nn][aa][bb][cc][dd] << ' ' << aa << ' ' << bb << ' ' << cc << ' ' << dd << '\n';}}}}for(int ii = 0; ii <= nn; ++ii){ for(int aa : {0, 1}){for(int bb : {0, 1}){for(int cc : {0, 1}){for(int dd : {0 , 1}){dp[ii][aa][bb][cc][dd] = 0;}}}}}}}}}}       }}}}}}}}}}}cout << Res << '\n';}}
signed main(){freopen("binary.in","r",stdin);freopen("binary.out","w",stdout);ios::sync_with_stdio(false), cin.tie(0), cout.tie(0);cin >> n >> k;// SubTask5 :: Main(n, k);if(n <= 20 && k <= 4)SubTask1 :: Main(n, k);else if(k == 1)SubTask2 :: Main(n, k);else if(k == 2)SubTask3 :: Main(n, k);else if(k == 3)SubTask4 :: Main(n, k);else SubTask5 :: Main(n, k);return 0;
}
// aolinpikepinbaodasai