結果
| 問題 | No.2382 Amidakuji M |
| ユーザー |
 tomo0608
|
| 提出日時 | 2023-07-14 21:58:00 |
| 言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
| 結果 |
AC
|
| 実行時間 | 75 ms / 2,000 ms |
| コード長 | 8,567 bytes |
| コンパイル時間 | 2,871 ms |
| コンパイル使用メモリ | 216,036 KB |
| 最終ジャッジ日時 | 2025-02-15 14:02:09 |
|
ジャッジサーバーID （参考情報） |
judge4 / 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
#pragma region competitive_programming#ifdef __LOCAL#define _GLIBCXX_DEBUG#endif#pragma GCC optimize("Ofast")#include<bits/stdc++.h>template<class T>struct Binary_Indexed_Tree {public:Binary_Indexed_Tree() :_n(0) {}Binary_Indexed_Tree(int n) : _n(n) {for (int i = 0; i < 2; i++)data[i].assign(n, 0);}void add(int l, int r, T x) { // [l, r)にxを加算assert(0 <= l && l < r && r <= _n);add_sub(0, l, -x * (l - 1));add_sub(0, r, x * (r - 1));add_sub(1, l, x);add_sub(1, r, -x);}void add(int p, T x) { // pにxを加算assert(0 <= p && p < _n);add(p, p + 1, x);}T sum(int r) { // [0, r)return sum_sub(0, r) + sum_sub(1, r) * (r - 1);}T sum(int l, int r) { // [l,r)assert(0 <= l && l <= r && r <= _n);return sum(r) - sum(l);}T operator[](int r) { return sum(r + 1) - sum(r); }int lower_bound(T w) { // \sum_{i=0}^{x}a_x >= wとなるような最小のx なければn, ただしa_xは全て非負であることが条件if (w <= 0)return 0;int x = 0, r = 1;while (r < _n)r = r << 1;for (int len = r; len > 0; len = len >> 1) {if (x + len < _n && sum(x, x + len) < w) {w -= sum(x, x + len);x += len;}}if (w > 0)x++;return x;}private:int _n;std::vector<T> data[2];void add_sub(int i, int p, T x) { // 0-indexedassert(0 <= p && p <= _n);p++; // 内部では1-indexedwhile (p <= _n) {data[i][p - 1] += x;p += p & -p;}}T sum_sub(int i, int p) {T s = 0;for (int idx = p; idx > 0; idx -= (idx & -idx)) {s += data[i][idx - 1];}return s;}};namespace tomo0608 {typedef long long ll;typedef long double ld;template <class T> using V = std::vector<T>;template <class T> using VV = V<V<T>>;template <class T> using VVV = V<VV<T>>;typedef std::pair<int, int> pii;typedef std::pair<long long, long long> pll;template<class... T>void input(T&... a) { (std::cin >> ... >> a); };#define INT(...) int __VA_ARGS__; IN(__VA_ARGS__)#define LL(...) long long __VA_ARGS__; IN(__VA_ARGS__)#define STR(...) string __VA_ARGS__; IN(__VA_ARGS__)#define DBL(...) double __VA_ARGS__; IN(__VA_ARGS__)#define VEC(type, name, size) std::vector<type> name(size);IN(name)#define VECVEC(type, name, h, w) std::vector<std::vector<type>> name(h, std::vector<type>(w));IN(name)template<class T1, class T2> std::istream& operator>>(std::istream& is, std::pair<T1, T2>& p) { is >> p.first >> p.second; return is; }template<class T1, class T2> std::ostream& operator<<(std::ostream& os, const std::pair<T1, T2>& p) { os << '(' << p.first << ", " << p.second <<')'; return os; }template<class T> std::istream& operator>>(std::istream& is, std::vector<T>& v) { for (auto& e : v) is >> e; return is; }template<class T> std::ostream& operator<<(std::ostream& os, const std::vector<T>& v) { for (auto& e : v) os << e << ' '; return os; }template<typename T> std::ostream& operator << (std::ostream& os, std::set<T>& set_var) { os << "{"; for (auto itr = set_var.begin(); itr !=set_var.end(); itr++) { os << *itr;++itr;if (itr != set_var.end()) os << ", ";itr--; }os << "}";return os; }template <typename T, typename U> std::ostream& operator<<(std::ostream& os, std::map<T, U>& map_var) { os << "{";for (auto itr = map_var.begin(); itr != map_var.end(); itr++) { os << *itr;itr++;if (itr != map_var.end()) os << ", ";itr--; }os << "}";return os; }void IN() {}template <class Head, class... Tail> void IN(Head& head, Tail &...tail) {std::cin >> head;IN(tail...);}void print() { std::cout << '\n'; }template<class T, class... Ts>void print(const T& a, const Ts&... b) { std::cout << a; (std::cout << ... << (std::cout << ' ', b)); std::cout <<'\n'; }void drop() { std::cout << '\n';exit(0); }template<class T, class... Ts>void drop(const T& a, const Ts&... b) { std::cout << a; (std::cout << ... << (std::cout << ' ', b)); std::cout <<'\n';exit(0); }#ifdef __LOCALvoid debug_out() { std::cerr << std::endl; }template < class Head, class... Tail> void debug_out(Head H, Tail... T) { std::cerr << ' ' << H; debug_out(T...); }#define debug(...) std::cerr << 'L' << __LINE__ << " [" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)#define dump(x) std::cerr << 'L' << __LINE__ << " " << #x << " = " << (x) << std::endl#else#define debug(...) (void(0))#define dump(x) (void(0))#endif#define rep1(a) for(long long i = 0; i < a; i++)#define rep2(i, a) for(long long i = 0; i < a; i++)#define rep3(i, a, b) for(long long i = a; i < b; i++)#define rep4(i, a, b, c) for(long long i = a; i < b; i += c)#define drep1(a) for(long long i = a-1; i >= 0; i--)#define drep2(i, a) for(long long i = a-1; i >= 0; i--)#define drep3(i, a, b) for(long long i = a-1; i >= b; i--)#define drep4(i, a, b, c) for(long long i = a-1; i >= b; i -= c)#define overload4(a, b, c, d, e, ...) e#define rep(...) overload4(__VA_ARGS__, rep4, rep3, rep2, rep1)(__VA_ARGS__)#define drep(...) overload4(__VA_ARGS__, drep4, drep3, drep2, drep1)(__VA_ARGS__)#define endl '\n'} // namespace tomo0608namespace tomo0608 {#define ALL(x) x.begin(),x.end()template <class T = long long, class S> T SUM(const S& v) { return accumulate(ALL(v), T(0)); }#define MIN(v) *min_element(ALL(v))#define MAX(v) *max_element(ALL(v))#define SORT(v) sort(ALL(v))#define REVERSE(v) reverse(ALL(v))#define RSORT(v) sort(ALL(v)); reverse(ALL(v))#define UNIQUE(x) SORT(x), x.erase(unique(ALL(x)), x.end())#define lb(c, x) distance((c).begin(), lower_bound(ALL(c), (x)))#define ub(c, x) distance((c).begin(), upper_bound(ALL(c), (x)))template <typename T> void zip(std::vector<T>& x) { std::vector<T> y = x;UNIQUE(y);for (int i = 0; i < x.size(); ++i) { x[i] = lb(y, x[i]); } }template<class T> using priority_queue_rev = std::priority_queue<T, std::vector<T>, std::greater<T>>;template<class T, class U> inline bool chmax(T& a, const U& b) { if (a < b) { a = b; return 1; } return 0; }template<class T, class U> inline bool chmin(T& a, const U& b) { if (a > b) { a = b; return 1; } return 0; }template<class T> inline int count_between(std::vector<T>& a, T l, T r) { return lower_bound(all(a), r) - lower_bound(all(a), l); } // [l, r)#define bittest(n, k) ((n >> k) & 1)int topbit(signed t) { return t == 0 ? -1 : 31 - __builtin_clz(t); }int topbit(long long t) { return t == 0 ? -1 : 63 - __builtin_clzll(t); }int lowbit(signed a) { return a == 0 ? 32 : __builtin_ctz(a); }int lowbit(long long a) { return a == 0 ? 64 : __builtin_ctzll(a); }#define perm(v) for(bool permrepflag = true; (permrepflag ? exchange(permrepflag, false) : next_permutation(ALL(v)));)template <typename T, typename S> T ceil(T x, S y) {assert(y);return (y < 0 ? ceil(-x, -y) : (x > 0 ? (x + y - 1) / y : x / y));}template <typename T, typename S> T floor(T x, S y) {assert(y);return (y < 0 ? floor(-x, -y) : (x > 0 ? x / y : x / y - (x % y == 0 ? 0 : 1)));}}//using namespace atcoder;using namespace std;using namespace tomo0608;int dx[8] = { 1, 0, -1, 0, 1, 1, -1, -1 };int dy[8] = { 0, 1, 0, -1, 1, -1, -1, 1 };// インタラクティブ問題のときは出力するたびにcout.flush();を忘れない!!!!!void solve();int main() {std::cin.tie(0);std::ios_base::sync_with_stdio(false);std::cout << std::setprecision(20);int codeforces = 1;//cin >> codeforces;while (codeforces--) {solve();}return 0;}#pragma endregionvoid solve() {LL(n, m);VEC(ll, p, n);Binary_Indexed_Tree<ll> BIT(n);ll x = 0;rep(i, n) {x += BIT.sum(p[i] - 1, n);BIT.add(p[i] - 1, 1);}if (x == 0) {drop(0);}if (x % 2 == 1) {if (m % 2 == 0)drop(-1);// mの奇数倍でx以上となればよいif (m >= x)drop(m);ll s = (x + m - 1) / m;if (s % 2 == 0)s++;drop(s * m);}else {if (m >= x) {if (m % 2)m *= 2;drop(m);}ll s = (x + m - 1) / m;if (m % 2 == 1 && s % 2 == 1)s++;drop(s * m);}}