結果
問題 | No.2327 Inversion Sum |
ユーザー |
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提出日時 | 2023-05-28 14:40:36 |
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 | 4,059 bytes |
コンパイル時間 | 2,108 ms |
コンパイル使用メモリ | 211,840 KB |
最終ジャッジ日時 | 2025-02-13 11:52:08 |
ジャッジサーバーID (参考情報) |
judge3 / judge2 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 3 |
other | AC * 30 |
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/segtree>int op(int x, int y) {return x + y;}int elem() {return 0;}using segtree = atcoder::segtree<int, op, elem>;#include <atcoder/modint>using mint = atcoder::modint998244353;int main() {int n, m; cin >> n >> m;auto l = vec<array<int, 2>>(uns, m);for (auto &[p, k] : l) {cin >> p >> k; --p; --k;}sort(begin(l), end(l), [](auto x, auto y) {return x[1] < y[1];});auto f = vec<mint>(uns, n + 1);f[0] = 1;for (int i = 1; i <= n; ++i) {f[i] = f[i - 1] * i;}mint ans = [&]() {mint sum = 0;segtree seg(n);for (auto [p, k] : l) {sum += seg.prod(p, n);seg.set(p, 1);}return sum * f[n - m];}();auto used = vec<char>(false, n);for (auto [p, k] : l) {used[p] = true;}segtree unused(n);for (int i = 0; i < n; ++i) {if (!used[i]) {unused.set(i, 1);}}int used1 = 0;for (auto [p, k] : l) {mint rem = k - used1++;mint upper = unused.prod(p, n);ans += upper * rem * f[max(0, n - m - 1)];}reverse(begin(l), end(l));int used2 = 0;for (auto [p, k] : l) {mint rem = (n - k - 1) - used2++;mint lower = unused.prod(0, p);ans += lower * rem * f[max(0, n - m - 1)];}mint count = n - m;ans += (count * (count - 1) / 2) * f[max(0, n - m - 2)] * (mint(max(1, n - m)) * max(0, n - m - 1) / 2);cout << ans.val() << endl;}