結果
問題 | No.2511 Mountain Sequence |
ユーザー |
![]() |
提出日時 | 2023-10-21 02:52:11 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 57 ms / 2,000 ms |
コード長 | 3,016 bytes |
コンパイル時間 | 1,863 ms |
コンパイル使用メモリ | 196,460 KB |
最終ジャッジ日時 | 2025-02-17 12:08:56 |
ジャッジサーバーID (参考情報) |
judge2 / judge1 |
(要ログイン)
ファイルパターン | 結果 |
---|---|
sample | AC * 3 |
other | AC * 32 |
ソースコード
#include <bits/stdc++.h>using namespace std;struct iofast_t {iofast_t() {ios::sync_with_stdio(false);cin.tie(nullptr);}} iofast;struct uns_t {} uns;template <typename Element, typename Head, typename ...Args>auto vec(Element init, Head arg, Args ...args) {if constexpr (sizeof...(Args) == 0) return vector(arg, init);else return vector(arg, vec(init, args...));}template <typename Element, typename Head, typename ...Args>auto vec(uns_t, Head arg, Args ...args) {return vec(Element(), arg, args...);}template <typename Container>auto distance(const Container &c, decltype(begin(c)) iter) {return distance(begin(c), iter);}template <typename RIter, typename Compare = less<typename iterator_traits<RIter>::value_type>>auto isort(RIter first, RIter last, Compare comp = Compare()) {vector<int> i(distance(first, last));iota(begin(i), end(i), 0);sort(begin(i), end(i), [&](auto x, auto y) {return comp(*(first + x), *(first + y));});return i;}template <typename, template <typename> typename, typename = void_t<>>struct detect : false_type {};template <typename T, template <typename> typename Check>struct detect<T, Check, void_t<Check<T>>> : true_type {};template <typename T, template <typename> typename Check>constexpr inline bool detect_v = detect<T, Check>::value;template <typename T>using has_member_sort = decltype(declval<T>().sort());template <typename Container, typename Compare = less<typename Container::value_type>>auto sorted(Container c, Compare comp = Compare()) {if constexpr (detect_v<Container, has_member_sort>) {c.sort(comp);return c;}else {sort(begin(c), end(c), comp);return c;}}template <typename Container, typename Compare = equal_to<typename Container::value_type>>auto uniqued(Container c, Compare comp = Compare()) {c.erase(unique(begin(c), end(c), comp), end(c));return c;}template <typename T, typename Compare = less<T>>T &chmin(T &l, T r, Compare &&f = less<T>()) { return l = min(l, r, f); }template <typename T, typename Compare = less<T>>T &chmax(T &l, T r, Compare &&f = less<T>()) { return l = max(l, r, f); }template <typename F>constexpr auto fix(F &&f) noexcept {return [f = std::tuple<F>(std::forward<F>(f))](auto &&...args) mutable {return std::get<0>(f)(fix(std::get<0>(f)), std::forward<decltype(args)>(args)...);};}#include <atcoder/modint>using mint = atcoder::modint998244353;int main() {int n, m; cin >> n >> m;auto f = vec<mint>(uns, m + m + 1);auto g = vec<mint>(uns, m + m + 1);f[0] = g[0] = 1;for (int i = 1; i <= m + m; ++i) {f[i] = f[i - 1] * i;g[i] = 1 / f[i];}auto comb = [&](int n, int r) {return f[n] * g[r] * g[n - r];};mint ans = 0;for (int i = (n + 2) / 2; i <= m; ++i) {ans += comb(2 * i - 2, n - 1);}cout << ans.val() << endl;}