結果
問題 | No.1989 Pairing Multiset |
ユーザー |
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提出日時 | 2022-06-26 13:46:37 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 59 ms / 2,000 ms |
コード長 | 4,399 bytes |
コンパイル時間 | 1,363 ms |
コンパイル使用メモリ | 126,916 KB |
最終ジャッジ日時 | 2025-01-30 00:52:32 |
ジャッジサーバーID (参考情報) |
judge1 / judge2 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 3 |
other | AC * 18 |
ソースコード
#include <algorithm>#include <array>#include <bitset>#include <cassert>#include <ciso646>#include <cmath>#include <complex>#include <cstdio>#include <functional>#include <iomanip>#include <iostream>#include <map>#include <queue>#include <random>#include <set>#include <stack>#include <string>#include <tuple>#include <unordered_map>#include <utility>#include <vector>using namespace std;typedef long long ll;const ll mod = 998244353;const ll INF = (ll)1000000007 * 1000000007;typedef pair<int, int> P;#define rep(i, n) for (int i = 0; i < n; i++)#define per(i, n) for (int i = n - 1; i >= 0; i--)#define Rep(i, sta, n) for (int i = sta; i < n; i++)#define Per(i, sta, n) for (int i = n - 1; i >= sta; i--)typedef long double ld;const ld eps = 1e-8;const ld pi = acos(-1.0);typedef pair<ll, ll> LP;int dx[8] = {1, -1, 0, 0, 1, 1, -1, -1};int dy[8] = {0, 0, 1, -1, 1, -1, 1, -1};template <class T>using max_heap = priority_queue<T>;template <class T>using min_heap = priority_queue<T, vector<T>, greater<>>;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 <int mod>struct ModInt {long long x;static constexpr int MOD = mod;ModInt() : x(0) {}ModInt(long long y) : x(y >= 0 ? y % mod : (mod - (-y) % mod) % mod) {}explicit operator int() const { return x; }ModInt &operator+=(const ModInt &p) {if ((x += p.x) >= mod) x -= mod;return *this;}ModInt &operator-=(const ModInt &p) {if ((x += mod - p.x) >= mod) x -= mod;return *this;}ModInt &operator*=(const ModInt &p) {x = (int)(1LL * x * p.x % mod);return *this;}ModInt &operator/=(const ModInt &p) {*this *= p.inverse();return *this;}ModInt operator-() const { return ModInt(-x); }ModInt operator+(const ModInt &p) const { return ModInt(*this) += p; }ModInt operator-(const ModInt &p) const { return ModInt(*this) -= p; }ModInt operator*(const ModInt &p) const { return ModInt(*this) *= p; }ModInt operator/(const ModInt &p) const { return ModInt(*this) /= p; }ModInt operator%(const ModInt &p) const { return ModInt(0); }bool operator==(const ModInt &p) const { return x == p.x; }bool operator!=(const ModInt &p) const { return x != p.x; }ModInt inverse() const {int a = x, b = mod, u = 1, v = 0, t;while (b > 0) {t = a / b;a -= t * b;swap(a, b);u -= t * v;swap(u, v);}return ModInt(u);}ModInt power(long long n) const {ModInt ret(1), mul(x);while (n > 0) {if (n & 1) ret *= mul;mul *= mul;n >>= 1;}return ret;}ModInt power(const ModInt p) const { return ((ModInt)x).power(p.x); }friend ostream &operator<<(ostream &os, const ModInt<mod> &p) {return os << p.x;}friend istream &operator>>(istream &is, ModInt<mod> &a) {long long x;is >> x;a = ModInt<mod>(x);return (is);}};using modint = ModInt<mod>;struct ModFac {public:vector<modint> f, i_f;int n;ModFac(int n_) {n = n_;f.resize(n + 1, 1);i_f.resize(n + 1, 1);for (int i = 0; i < n; i++) {f[i + 1] = f[i] * (modint)(i + 1);}i_f[n] = f[n].power(mod - 2);for (int i = n - 1; i >= 0; i--) {i_f[i] = i_f[i + 1] * (modint)(i + 1);}}ModFac(modint n_) {n = (int)n_;f.resize(n + 1, 1);i_f.resize(n + 1, 1);for (int i = 0; i < n; i++) {f[i + 1] = f[i] * (modint)(i + 1);}i_f[n] = f[n].power(mod - 2);for (int i = n - 1; i >= 0; i--) {i_f[i] = i_f[i + 1] * (modint)(i + 1);}}modint factorial(int x) {// cout << f.size() << endl;return f[x];}modint inv_factorial(int x) { return i_f[x]; }modint comb(int m, int k) {if (m < 0 or k < 0) return 0;if (m < k) return 0;return f[m] * i_f[k] * i_f[m - k];}};ModFac MF(3000010);int N, M;void solve() {cin >> N >> M;modint C = 1;rep(i, 2 * N) { C *= (modint)(M + 2 * N - i); }C *= MF.inv_factorial(2 * N);modint ans = (modint)N * M / (modint)(2 * N + 1) * C;cout << ans << endl;}int main() {ios::sync_with_stdio(false);cin.tie(0);cout << fixed << setprecision(50);solve();}