結果

問題 No.2383 Naphthol
ユーザー cn_449cn_449
提出日時 2023-07-14 22:45:31
言語 C++17
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 31 ms / 2,000 ms
コード長 4,309 bytes
コンパイル時間 4,178 ms
コンパイル使用メモリ 200,416 KB
最終ジャッジ日時 2025-02-15 14:25:45
ジャッジサーバーID
（参考情報） 		judge3 / judge4
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 3
other AC * 18
権限があれば一括ダウンロードができます

ソースコード

diff # 

#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <string>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <iomanip>
#include <utility>
#include <tuple>
#include <functional>
#include <bitset>
#include <cassert>
#include <complex>
#include <stdio.h>
#include <time.h>
#include <numeric>
#include <random>
#include <unordered_set>
#include <unordered_map>
#define all(a) (a).begin(), (a).end()
#define rep(i, n) for (ll i = 0; i < (n); i++)
#define req(i, a, b) for (ll i = (a); i < (b); i++)
#define pb push_back
#define debug(x) cerr << __LINE__ << ' ' << #x << ':' << (x) << '\n'
#define debug2(x, y) cerr << __LINE__ << ' ' << #x << ':' << (x) << ',' << #y << ':' << (y) << '\n'
#define debug3(x, y, z) cerr << __LINE__ << ' ' << #x << ':' << (x) << ',' << #y << ':' << (y) << ',' << #z << ':' << (z) << '\n'
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
using namespace std;
typedef long long ll;
typedef unsigned int uint;
typedef unsigned long long ull;
typedef long double ld;
template<class T> using P = pair<T, T>;
template<class T> using pri_s = priority_queue<T, vector<T>, greater<T>>;
template<class T> using pri_b = priority_queue<T>;
constexpr int inf = 1000000010;
constexpr int inf2 = 2000000010;
constexpr ll INF = 1000000000000000010;
constexpr ll INF4 = 4000000000000000010;
constexpr int mod1e9 = 1000000007;
constexpr int mod998 = 998244353;
constexpr ld eps = 1e-12;
constexpr ld pi = 3.141592653589793238;
constexpr ll ten(int n) { return n ? 10 * ten(n - 1) : 1; };
int dx[] = { 1,0,-1,0,1,1,-1,-1,0 }; int dy[] = { 0,1,0,-1,1,-1,1,-1,0 };
ll mul(ll a, ll b) { return (b != 0 && a > INF / b ? INF : a * b); }
void fail() { cout << "-1\n"; exit(0); } void no() { cout << "No\n"; exit(0); }
template<class T> void er(T a) { cout << a << '\n'; exit(0); }
template<class T, class U> inline bool chmax(T &a, const U &b) { if (a < b) { a = b; return true; } return false; }
template<class T, class U> inline bool chmin(T &a, const U &b) { if (a > b) { a = b; return true; } return false; }
template<class T> istream &operator >>(istream &s, vector<T> &v) { for (auto &e : v) s >> e; return s; }
template<class T> ostream &operator <<(ostream &s, const vector<T> &v) { for (auto &e : v) s << e << ' '; return s; }
template<class T, class U> ostream &operator << (ostream &s, const pair<T, U> &p) { s << p.first << ' ' << p.second; return s; }

struct fastio {
	fastio() {
		cin.tie(0); cout.tie(0);
		ios::sync_with_stdio(false);
		cout << fixed << setprecision(20);
		cerr << fixed << setprecision(20);
	}
}fastio_;

#include <atcoder/all>
using namespace atcoder;

constexpr ll mod = mod998;
using mint = static_modint<mod>;

istream &operator >>(istream &s, mint &m) { ll y; s >> y; m = y; return s; }
ostream &operator <<(ostream &s, mint &m) { return s << m.val(); }
ostream &operator <<(ostream &s, const vector<mint> &v) { for (auto &e : v) s << e.val() << ' '; return s; }

vector<mint> fac, inv, facinv;

void modcalc(int n) {
	fac.resize(n); inv.resize(n); facinv.resize(n);
	fac[0] = 1; fac[1] = 1; inv[1] = 1;
	facinv[0] = 1; facinv[1] = 1;
	for (ll i = 2; i < n; i++) {
		fac[i] = fac[i - 1] * i;
		inv[i] = -inv[mod % i] * (mod / i);
		facinv[i] = facinv[i - 1] * inv[i];
	}
}

mint comb(ll n, ll k) {
	if (n < 0 || k < 0 || n < k) return 0;
	return fac[n] * facinv[k] * facinv[n - k];
}

mint perm(ll n, ll k) {
	if (n < 0 || k < 0 || n < k) return 0;
	return fac[n] * facinv[n - k];
}

mint hom(ll n, ll k) {
	if (n < 0 || k < 0 || n == 0 && k > 0) return 0;
	if (n == 0 && k == 0) return 1;
	return fac[n + k - 1] * facinv[k] * facinv[n - 1];
}

int main() {
	modcalc(300000);
	ll n, k;
	cin >> n >> k;
	if(n == 1){
		vector<int> v = {1, 1, 3, 3, 3, 1, 1};
		cout << v[k] << '\n';
		return 0;
	}
    //assert(k % 2 == 1 or n % 2 == 0);
	mint a = 0, b = 0, c = 0;
	if(k % 4 == 0 or (n % 2 == 1 && k % 2 == 0)) c = comb(n / 2 + 1, k / 4);
	if(n % 2 == 0){
		if(k % 2 == 0) b += comb(n + 2, k / 2) - c;
	}
	else{
		if(k % 2 == 0) {
			b += comb(n + 1, k / 2) - c;
			b += comb(n + 1, k / 2 - 1);
		}
		else{
			b += comb(n + 1, k / 2);
		}
	}
	b *= 2;
	if(k % 2 == 0) b += comb(n + 2, k / 2) - c;
	a = comb(2 * n + 4, k);
	a -= b + c;
	mint ans = a * inv[4] + b * inv[2] + c;
	cout << ans << '\n';
}
0