結果
問題 |
No.2382 Amidakuji M
|
ユーザー |
![]() |
提出日時 | 2023-07-14 21:43:16 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 25 ms / 2,000 ms |
コード長 | 5,249 bytes |
コンパイル時間 | 1,029 ms |
コンパイル使用メモリ | 124,692 KB |
最終ジャッジ日時 | 2025-02-15 13:50:33 |
ジャッジサーバーID (参考情報) |
judge1 / judge3 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 3 |
other | AC * 19 |
ソースコード
#ifndef LOCAL #define FAST_IO #endif // ============ #include <algorithm> #include <array> #include <bitset> #include <cassert> #include <cmath> #include <iomanip> #include <iostream> #include <list> #include <map> #include <numeric> #include <queue> #include <random> #include <set> #include <stack> #include <string> #include <tuple> #include <unordered_map> #include <unordered_set> #include <utility> #include <vector> #define OVERRIDE(a, b, c, d, ...) d #define REP2(i, n) for (i32 i = 0; i < (i32)(n); ++i) #define REP3(i, m, n) for (i32 i = (i32)(m); i < (i32)(n); ++i) #define REP(...) OVERRIDE(__VA_ARGS__, REP3, REP2)(__VA_ARGS__) #define PER(i, n) for (i32 i = (i32)(n) - 1; i >= 0; --i) #define ALL(x) begin(x), end(x) using namespace std; using u32 = unsigned int; using u64 = unsigned long long; using i32 = signed int; using i64 = signed long long; using f64 = double; using f80 = long double; template <typename T> using Vec = vector<T>; template <typename T> bool chmin(T &x, const T &y) { if (x > y) { x = y; return true; } return false; } template <typename T> bool chmax(T &x, const T &y) { if (x < y) { x = y; return true; } return false; } #ifdef INT128 using u128 = __uint128_t; using i128 = __int128_t; istream &operator>>(istream &is, i128 &x) { i64 v; is >> v; x = v; return is; } ostream &operator<<(ostream &os, i128 x) { os << (i64)x; return os; } istream &operator>>(istream &is, u128 &x) { u64 v; is >> v; x = v; return is; } ostream &operator<<(ostream &os, u128 x) { os << (u64)x; return os; } #endif [[maybe_unused]] constexpr i32 INF = 1000000100; [[maybe_unused]] constexpr i64 INF64 = 3000000000000000100; struct SetUpIO { SetUpIO() { #ifdef FAST_IO ios::sync_with_stdio(false); cin.tie(nullptr); #endif cout << fixed << setprecision(15); } } set_up_io; // ============ #ifdef DEBUGF #else #define DBG(x) (void)0 #endif // ============ #include <cassert> #include <vector> // ============ #include <limits> #include <utility> template <typename T> struct Add { using Value = T; static Value id() { return T(0); } static Value op(const Value &lhs, const Value &rhs) { return lhs + rhs; } static Value inv(const Value &x) { return -x; } }; template <typename T> struct Mul { using Value = T; static Value id() { return Value(1); } static Value op(const Value &lhs, const Value &rhs) { return lhs * rhs; } static Value inv(const Value &x) { return Value(1) / x; } }; template <typename T> struct Min { using Value = T; static Value id() { return std::numeric_limits<T>::max(); } static Value op(const Value &lhs, const Value &rhs) { return std::min(lhs, rhs); } }; template <typename T> struct Max { using Value = T; static Value id() { return std::numeric_limits<Value>::min(); } static Value op(const Value &lhs, const Value &rhs) { return std::max(lhs, rhs); } }; template <typename T> struct Xor { using Value = T; static Value id() { return T(0); } static Value op(const Value &lhs, const Value &rhs) { return lhs ^ rhs; } static Value inv(const Value &x) { return x; } }; template <typename Monoid> struct Reversible { using Value = std::pair<typename Monoid::Value, typename Monoid::Value>; static Value id() { return Value(Monoid::id(), Monoid::id()); } static Value op(const Value &v1, const Value &v2) { return Value( Monoid::op(v1.first, v2.first), Monoid::op(v2.second, v1.second)); } }; // ============ template <typename CommutativeGroup> class FenwickTree { public: using Value = typename CommutativeGroup::Value; private: std::vector<Value> data; public: FenwickTree(int n) : data(n, CommutativeGroup::id()) {} void add(int idx, const Value &x) { assert(idx >= 0 && idx < (int) data.size()); for (; idx < (int) data.size(); idx |= idx + 1) { data[idx] = CommutativeGroup::op(data[idx], x); } } Value sum(int r) const { assert(r >= 0 && r <= (int) data.size()); Value ret = CommutativeGroup::id(); for (; r > 0; r &= r - 1) { ret = CommutativeGroup::op(ret, data[r - 1]); } return ret; } Value sum(int l, int r) const { assert(l >= 0 && l <= r && r <= (int) data.size()); return CommutativeGroup::op(sum(r), CommutativeGroup::inv(sum(l))); } }; template <typename T> using FenwickTreeAdd = FenwickTree<Add<T>>; // ============ int main() { i32 n; i64 m; cin >> n >> m; Vec<i32> p(n); REP(i, n) { cin >> p[i]; --p[i]; } FenwickTreeAdd<i32> fw(n); i64 inv = 0; REP(i, n) { inv += fw.sum(p[i] + 1, n); fw.add(p[i], 1); } if (inv % 2 == 1 && m % 2 == 0) { cout << -1 << '\n'; } else { i64 k = (inv + m - 1) / m * m; if (k % 2 != inv % 2) { k += m; } cout << k << '\n'; } }