結果
問題 | No.1311 Reverse Permutation Index |
ユーザー |
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提出日時 | 2020-12-08 20:48:11 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 2 ms / 1,500 ms |
コード長 | 4,026 bytes |
コンパイル時間 | 1,723 ms |
コンパイル使用メモリ | 152,396 KB |
最終ジャッジ日時 | 2025-01-16 19:55:43 |
ジャッジサーバーID (参考情報) |
judge5 / judge4 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 2 |
other | AC * 6 |
ソースコード
#include <limits> #include <initializer_list> #include <utility> #include <bitset> #include <tuple> #include <type_traits> #include <functional> #include <string> #include <array> #include <deque> #include <list> #include <queue> #include <stack> #include <vector> #include <map> #include <set> #include <unordered_map> #include <unordered_set> #include <iterator> #include <algorithm> #include <complex> #include <random> #include <numeric> #include <iostream> #include <iomanip> #include <sstream> #include <regex> #include <cassert> #include <cstddef> #include <variant> #define endl codeforces #define ALL(v) std::begin(v), std::end(v) #define ALLR(v) std::rbegin(v), std::rend(v) using ll = std::int64_t; using ull = std::uint64_t; using pii = std::pair<int, int>; using tii = std::tuple<int, int, int>; using pll = std::pair<ll, ll>; using tll = std::tuple<ll, ll, ll>; using size_type = ssize_t; template <typename T> using vec = std::vector<T>; template <typename T> using vvec = vec<vec<T>>; template <typename T> const T& var_min(const T &t) { return t; } template <typename T> const T& var_max(const T &t) { return t; } template <typename T, typename... Tail> const T& var_min(const T &t, const Tail&... tail) { return std::min(t, var_min(tail...)); } template <typename T, typename... Tail> const T& var_max(const T &t, const Tail&... tail) { return std::max(t, var_max(tail...)); } template <typename T, typename... Tail> void chmin(T &t, const Tail&... tail) { t = var_min(t, tail...); } template <typename T, typename... Tail> void chmax(T &t, const Tail&... tail) { t = var_max(t, tail...); } template <typename T, std::size_t Head, std::size_t... Tail> struct multi_dim_array { using type = std::array<typename multi_dim_array<T, Tail...>::type, Head>; }; template <typename T, std::size_t Head> struct multi_dim_array<T, Head> { using type = std::array<T, Head>; }; template <typename T, std::size_t... Args> using mdarray = typename multi_dim_array<T, Args...>::type; template <typename T, typename F, typename... Args> void fill_seq(T &t, F f, Args... args) { if constexpr (std::is_invocable<F, Args...>::value) { t = f(args...); } else { for (size_type i = 0; i < t.size(); i++) fill_seq(t[i], f, args..., i); } } template <typename T> vec<T> make_v(size_type sz) { return vec<T>(sz); } template <typename T, typename... Tail> auto make_v(size_type hs, Tail&&... ts) { auto v = std::move(make_v<T>(std::forward<Tail>(ts)...)); return vec<decltype(v)>(hs, v); } namespace init__ { struct InitIO { InitIO() { std::cin.tie(nullptr); std::ios_base::sync_with_stdio(false); std::cout << std::fixed << std::setprecision(30); } } init_io; } template <typename T> T ceil_pow2(T bound) { T ret = 1; while (ret < bound) ret *= 2; return ret; } template <typename T> T ceil_div(T a, T b) { return a / b + !!(a % b); } vec<ll> fact(21); void restore(ll ord, vec<ll> &rs, ll n, vec<ll> &res) { if (n == 0) return; ll d = ord / fact[n - 1]; ord %= fact[n - 1]; res.push_back(rs[d]); rs.erase(rs.begin() + d); restore(ord, rs, n - 1, res); } vec<ll> restore(ll ord, ll n) { vec<ll> res, rs(n); std::iota(ALL(rs), 0ll); res.reserve(n); restore(ord, rs, n, res); return res; } ll index(const vec<ll> &aim, vec<ll> &rs, const ll n, ll i) { if (rs.empty()) return 0; auto ite = std::find(ALL(rs), aim[i]); ll ord = std::distance(rs.begin(), ite); rs.erase(ite); return fact[n - 1 - i] * ord + index(aim, rs, n, i + 1); } ll index(const vec<ll> &aim, const ll n) { vec<ll> rs(n); std::iota(ALL(rs), 0ll); return index(aim, rs, n, 0); } int main() { ll s, n; std::cin >> s >> n; fact[0] = 1; for (ll i = 1; i <= n; i++) fact[i] = fact[i - 1] * i; auto res = std::move(restore(s, n)); vec<ll> inv(n); for (ll i = 0; i < n; i++) inv[res[i]] = i; std::cout << index(inv, n) << "\n"; return 0; }