結果
| 問題 | No.2977 Kth Xor Pair |
| ユーザー |
 dyktr_06
|
| 提出日時 | 2024-12-02 04:44:41 |
| 言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
| 結果 |
AC
|
| 実行時間 | 1,700 ms / 3,000 ms |
| コード長 | 8,897 bytes |
| コンパイル時間 | 2,159 ms |
| コンパイル使用メモリ | 203,524 KB |
| 最終ジャッジ日時 | 2025-02-26 10:32:50 |
|
ジャッジサーバーID （参考情報） |
judge2 / judge1 |
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| ファイルパターン | 結果 |
|---|---|
| sample | AC * 2 |
| other | AC * 34 |
ソースコード
#include <bits/stdc++.h>using namespace std;#define overload4(_1, _2, _3, _4, name, ...) name#define rep1(n) for(int i = 0; i < (int)(n); ++i)#define rep2(i, n) for(int i = 0; i < (int)(n); ++i)#define rep3(i, a, b) for(int i = (a); i < (int)(b); ++i)#define rep4(i, a, b, c) for(int i = (a); i < (int)(b); i += (c))#define rep(...) overload4(__VA_ARGS__, rep4, rep3, rep2, rep1)(__VA_ARGS__)#define rrep(i,n) for(int i = (int)(n) - 1; i >= 0; --i)#define ALL(a) (a).begin(), (a).end()#define Sort(a) (sort((a).begin(), (a).end()))#define RSort(a) (sort((a).rbegin(), (a).rend()))#define UNIQUE(a) (a.erase(unique((a).begin(), (a).end()), (a).end()))typedef long long int ll;typedef unsigned long long ul;typedef long double ld;typedef vector<int> vi;typedef vector<long long> vll;typedef vector<char> vc;typedef vector<string> vst;typedef vector<double> vd;typedef vector<long double> vld;typedef pair<long long, long long> P;template<class T> long long sum(const T &a){ return accumulate(a.begin(), a.end(), 0LL); }template<class T> auto min(const T &a){ return *min_element(a.begin(), a.end()); }template<class T> auto max(const T &a){ return *max_element(a.begin(), a.end()); }const long long MINF = 0x7fffffffffff;const long long INF = 0x1fffffffffffffff;const long long MOD = 998244353;const long double EPS = 1e-9;const long double PI = acos(-1);template<class T> inline bool chmax(T &a, T b) { if(a < b) { a = b; return 1; } return 0; }template<class T> inline bool chmin(T &a, T b) { if(a > b) { a = b; return 1; } return 0; }template<typename T1, typename T2> istream &operator>>(istream &is, pair<T1, T2> &p){ is >> p.first >> p.second; return is; }template<typename T1, typename T2> ostream &operator<<(ostream &os, const pair<T1, T2> &p){ os << "(" << p.first << ", " << p.second << ")"; returnos; }template<typename T> istream &operator>>(istream &is, vector<T> &v){ for(T &in : v) is >> in; return is; }template<typename T> ostream &operator<<(ostream &os, const vector<T> &v){ for(int i = 0; i < (int) v.size(); ++i){ os << v[i] << (i + 1 != (int) v.size() ? " " : ""); } return os; }template <typename T, typename S> ostream &operator<<(ostream &os, const map<T, S> &mp){ for(auto &[key, val] : mp){ os << key << ":" << val << " ";} return os; }template <typename T> ostream &operator<<(ostream &os, const set<T> &st){ auto itr = st.begin(); for(int i = 0; i < (int) st.size(); ++i){ os << *itr<< (i + 1 != (int) st.size() ? " " : ""); itr++; } return os; }template <typename T> ostream &operator<<(ostream &os, const multiset<T> &st){ auto itr = st.begin(); for(int i = 0; i < (int) st.size(); ++i){ os <<*itr << (i + 1 != (int) st.size() ? " " : ""); itr++; } return os; }template <typename T> ostream &operator<<(ostream &os, queue<T> q){ while(q.size()){ os << q.front() << " "; q.pop(); } return os; }template <typename T> ostream &operator<<(ostream &os, deque<T> q){ while(q.size()){ os << q.front() << " "; q.pop_front(); } return os; }template <typename T> ostream &operator<<(ostream &os, stack<T> st){ while(st.size()){ os << st.top() << " "; st.pop(); } return os; }template <class T, class Container, class Compare> ostream &operator<<(ostream &os, priority_queue<T, Container, Compare> pq){ while(pq.size()){ os<< pq.top() << " "; pq.pop(); } return os; }template <typename T>long long binary_search(long long ok, long long ng, T check){while(abs(ok - ng) > 1){long long mid = (ok + ng) / 2;if(check(mid)) ok = mid;else ng = mid;}return ok;}template <typename T>long double binary_search_real(long double ok, long double ng, T check, int iter = 100){for(int i = 0; i < iter; ++i){long double mid = (ok + ng) / 2;if(check(mid)) ok = mid;else ng = mid;}return ok;}template <typename T>long long trisum(T a, T b){long long res = ((b - a + 1) * (a + b)) / 2;return res;}template <typename T>T intpow(T x, int n){T ret = 1;while(n > 0) {if(n & 1) (ret *= x);(x *= x);n >>= 1;}return ret;}template <typename T>T getReminder(T a, T b){if(b == 0) return -1;if(a >= 0 && b > 0){return a % b;} else if(a < 0 && b > 0){return ((a % b) + b) % b;} else if(a >= 0 && b < 0){return a % b;} else{return (abs(b) - abs(a % b)) % b;}}template<class T, class U> inline T vin(T &vec, U n) { vec.resize(n); for(int i = 0; i < (int) n; ++i) cin >> vec[i]; return vec; }template<class T> inline void vout(T vec, string s = "\n"){ for(auto x : vec) cout << x << s; }template<class... T> void in(T&... a){ (cin >> ... >> a); }void out(){ cout << '\n'; }template<class T, class... Ts> void out(const T &a, const Ts&... b){ cout << a; (cout << ... << (cout << ' ', b)); cout << '\n'; }template<class T, class U> void inGraph(vector<vector<T>> &G, U n, U m, bool directed = false){ G.resize(n); for(int i = 0; i < m; ++i){ int a, b;cin >> a >> b; a--, b--; G[a].push_back(b); if(!directed) G[b].push_back(a); } }// https://ei1333.github.io/library/structure/trie/binary-trie.hpp.htmltemplate <typename T, int MAX_LOG, typename D = int>struct BinaryTrie {public:struct Node {Node *nxt[2];D exist;vector<int> accept;Node() : nxt{nullptr, nullptr}, exist(0) {}};Node *root;explicit BinaryTrie() : root(new Node()) {}explicit BinaryTrie(Node *root) : root(root) {}void add(const T &bit, int idx = -1, D delta = 1, T xor_val = 0) {root = add(root, bit, idx, MAX_LOG, delta, xor_val);}void erase(const T &bit, T xor_val = 0) { add(bit, -1, -1, xor_val); }Node *find(const T &bit, T xor_val = 0) {return find(root, bit, MAX_LOG, xor_val);}D count(const T &bit, T xor_val = 0) {auto node = find(bit, xor_val);return node ? node->exist : 0;}pair<T, Node *> min_element(T xor_val = 0) {assert(root->exist > 0);return kth_element(0, xor_val);}pair<T, Node *> max_element(T xor_val = 0) {assert(root->exist > 0);return kth_element(root->exist - 1, xor_val);}pair<T, Node *> kth_element(D k, T xor_val = 0) { // 0-indexedassert(0 <= k && k < root->exist);return kth_element(root, k, MAX_LOG, xor_val);}D count_less(const T &bit, T xor_val = 0) { // < bitreturn count_less(root, bit, MAX_LOG, xor_val);}private:virtual Node *clone(Node *t) { return t; }Node *add(Node *t, T bit, int idx, int depth, D x, T xor_val,bool need = true) {if (need) t = clone(t);if (depth == -1) {t->exist += x;if (idx >= 0) t->accept.emplace_back(idx);} else {bool f = (xor_val >> depth) & 1;auto &to = t->nxt[f ^ ((bit >> depth) & 1)];if (!to) to = new Node(), need = false;to = add(to, bit, idx, depth - 1, x, xor_val, need);t->exist += x;}return t;}Node *find(Node *t, T bit, int depth, T xor_val) {if (depth == -1) {return t;} else {bool f = (xor_val >> depth) & 1;auto &to = t->nxt[f ^ ((bit >> depth) & 1)];return to ? find(to, bit, depth - 1, xor_val) : nullptr;}}pair<T, Node *> kth_element(Node *t, D k, int bit_index,T xor_val) { // 0-indexedif (bit_index == -1) {return {0, t};} else {bool f = (xor_val >> bit_index) & 1;if ((t->nxt[f] ? t->nxt[f]->exist : 0) <= k) {auto ret =kth_element(t->nxt[f ^ 1], k - (t->nxt[f] ? t->nxt[f]->exist : 0),bit_index - 1, xor_val);ret.first |= T(1) << bit_index;return ret;} else {return kth_element(t->nxt[f], k, bit_index - 1, xor_val);}}}D count_less(Node *t, const T &bit, int bit_index, T xor_val) {if (bit_index == -1) return 0;D ret = 0;bool f = (xor_val >> bit_index) & 1;if ((bit >> bit_index & 1) and t->nxt[f]) ret += t->nxt[f]->exist;if (t->nxt[f ^ (bit >> bit_index & 1)])ret += count_less(t->nxt[f ^ (bit >> bit_index & 1)], bit, bit_index - 1,xor_val);return ret;}};ll T;void input(){in(T);}void solve(){ll n, k; in(n, k);vll a(n); in(a);Sort(a);BinaryTrie<ll, 30> bt;rep(i, n) bt.add(a[i]);auto f = [&](ll x){ll s = 0;rep(i, n){if(s + (n * (n - i)) < k){return false;}s += bt.count_less(x + 1, a[i]);if(s >= (k * 2) + n){return true;}}return false;};out(binary_search(1LL << 30, -1LL, f));}int main(){ios::sync_with_stdio(false);cin.tie(nullptr);cout << fixed << setprecision(20);T = 1;// input();while(T--) solve();}