結果
| 問題 |
No.2977 Kth Xor Pair
|
| ユーザー |
 dyktr_06
|
| 提出日時 | 2024-12-02 04:24:28 |
| 言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
| 結果 |
TLE
|
| 実行時間 | - |
| コード長 | 10,637 bytes |
| コンパイル時間 | 2,523 ms |
| コンパイル使用メモリ | 210,180 KB |
| 最終ジャッジ日時 | 2025-02-26 10:28:43 |
|
ジャッジサーバーID （参考情報） |
judge2 / judge2 |
（要ログイン）
| ファイルパターン | 結果 |
|---|---|
| sample | AC * 2 |
| other | AC * 5 TLE * 2 -- * 27 |
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 << ")"; return os; }
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); } }
template <typename T, int MAX_LOG, int NODES = 1 << 23>
struct BinaryTrie{
struct Node{
Node *nxt[2];
int exist;
vector<int> accept;
Node() {}
};
Node *pool;
int pid;
T lazy;
Node *nil;
Node *root;
BinaryTrie() : pid(0), lazy(0), nil(nullptr){
pool = new Node[NODES];
nil = _new();
nil->nxt[0] = nil->nxt[1] = root = nil;
}
Node *_new(const int exist_ = 0, const int id = -1){
pool[pid].nxt[0] = pool[pid].nxt[1] = nil;
pool[pid].exist = exist_;
if(id != -1) pool[pid].accept.push_back(id);
return &(pool[pid++]);
}
Node *merge(Node *l, Node *r){
pool[pid].nxt[0] = l;
pool[pid].nxt[1] = r;
pool[pid].exist = l->exist + r->exist;
return &(pool[pid++]);
}
private:
Node *insert_(const T &x, const int id, Node *n, const int bit_idx){
if(bit_idx == -1) {
if(n == nil){
return _new(1, id);
}
n->exist++;
n->accept.push_back(id);
return n;
}
if(((lazy >> bit_idx) & 1) == ((x >> bit_idx) & 1)){
return merge(insert_(x, id, n->nxt[0], bit_idx - 1), n->nxt[1]);
} else{
return merge(n->nxt[0], insert_(x, id, n->nxt[1], bit_idx - 1));
}
}
Node *erase_(const T &x, const int id, Node *n, const int bit_idx){
if(bit_idx == -1){
n->exist--;
return n;
}
if(((lazy >> bit_idx) & 1) == ((x >> bit_idx) & 1)){
return merge(erase_(x, id, n->nxt[0], bit_idx - 1), n->nxt[1]);
} else{
return merge(n->nxt[0], erase_(x, id, n->nxt[1], bit_idx - 1));
}
}
pair<int, vector<int> &> find_(const T &x, Node *n, const int bit_idx){
if(bit_idx == -1){
return pair<int, vector<int> &>(n->exist, n->accept);
}
if(((lazy >> bit_idx) & 1) == ((x >> bit_idx) & 1)){
return find_(x, n->nxt[0], bit_idx - 1);
} else{
return find_(x, n->nxt[1], bit_idx - 1);
}
}
pair<T, vector<int> &> max_element_(Node *n, const int bit_idx) {
if(bit_idx == -1){
return pair<T, vector<int> &>(0, n->accept);
}
if(n->nxt[~(lazy >> bit_idx) & 1]->exist){
auto ret = max_element_(n->nxt[~(lazy >> bit_idx) & 1], bit_idx - 1);
ret.first |= T(1) << bit_idx;
return ret;
}
return max_element_(n->nxt[(lazy >> bit_idx) & 1], bit_idx - 1);
}
pair<T, vector<int> &> min_element_(Node *n, const int bit_idx){
if(bit_idx == -1){
return pair<T, vector<int> &>(0, n->accept);
}
if(n->nxt[(lazy >> bit_idx) & 1]->exist){
return min_element_(n->nxt[(lazy >> bit_idx) & 1], bit_idx - 1);
}
auto ret = min_element_(n->nxt[~(lazy >> bit_idx) & 1], bit_idx - 1);
ret.first |= T(1) << bit_idx;
return ret;
}
// 1-indexed, minimum-kth
pair<T, vector<int> &> kth_element_(Node *n, const int k, const int bit_idx){
if(bit_idx == -1){
return pair<T, vector<int> &>(0, n->accept);
}
int ex0 = n->nxt[(lazy >> bit_idx) & 1]->exist;
if(ex0 < k){
auto ret = kth_element_(n->nxt[~(lazy >> bit_idx) & 1], k - ex0, bit_idx - 1);
ret.first |= T(1) << bit_idx;
return ret;
}
return kth_element_(n->nxt[(lazy >> bit_idx) & 1], k, bit_idx - 1);
}
int count_less_(Node *n, const T &x, const int bit_idx) {
if(bit_idx == -1){
return 0;
}
int ret = 0;
bool f = (lazy >> bit_idx) & 1;
if((x >> bit_idx & 1) && n->nxt[f]){
ret += n->nxt[f]->exist;
}
if(n->nxt[f ^ (x >> bit_idx & 1)]){
ret += count_less_(n->nxt[f ^ (x >> bit_idx & 1)], x, bit_idx - 1);
}
return ret;
}
public:
void insert(const T &x, const int id = -1){
root = insert_(x, id, root, MAX_LOG);
}
void erase(const T &x, const int id = -1){
root = erase_(x, id, root, MAX_LOG);
}
pair<int, vector<int> &> find(const T &x){
return find_(x, root, MAX_LOG);
}
pair<T, vector<int> &> max_element(){
return max_element_(root, MAX_LOG);
}
pair<T, vector<int> &> min_element(){
return min_element_(root, MAX_LOG);
}
pair<T, vector<int> &> kth_element(const int k){
return kth_element_(root, k, MAX_LOG);
}
int count_less(const T &x){
return count_less_(root, x, MAX_LOG);
}
size_t size() const {
if(root->exist <= 0){
return 0;
}
return root->exist;
}
bool empty() const {
return size() == 0;
}
void operate_xor(const T &x){
lazy ^= x;
}
};
ll T;
void input(){
in(T);
}
void solve(){
ll n, k; in(n, k);
vll a(n); in(a);
BinaryTrie<ll, 30> bt;
auto f = [&](ll x){
ll s = 0;
rep(i, n){
bt.operate_xor(a[i]);
s += bt.count_less(x + 1);
bt.operate_xor(a[i]);
bt.insert(a[i]);
}
rep(i, n) bt.erase(a[i]);
return s >= k;
};
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();
}