Submission #967521

#	Time	Username	Problem	Language	Result	Execution time	Memory
967521		marvinthang	Abracadabra (CEOI22_abracadabra)	C++17	100 / 100	508 ms	48596 KiB

Main

/*************************************
*    author: marvinthang             *
*    created: 22.04.2024 16:32:37    *
*************************************/

#include <bits/stdc++.h>

using namespace std;

#define                  fi  first
#define                  se  second
#define                left  ___left
#define               right  ___right
#define                TIME  (1.0 * clock() / CLOCKS_PER_SEC)
#define             MASK(i)  (1LL << (i))
#define           BIT(x, i)  ((x) >> (i) & 1)
#define  __builtin_popcount  __builtin_popcountll
#define              ALL(v)  (v).begin(), (v).end()
#define           REP(i, n)  for (int i = 0, _n = (n); i < _n; ++i)
#define          REPD(i, n)  for (int i = (n); i-- > 0; )
#define        FOR(i, a, b)  for (int i = (a), _b = (b); i < _b; ++i) 
#define       FORD(i, b, a)  for (int i = (b), _a = (a); --i >= _a; ) 
#define       FORE(i, a, b)  for (int i = (a), _b = (b); i <= _b; ++i) 
#define      FORDE(i, b, a)  for (int i = (b), _a = (a); i >= _a; --i) 
#define        scan_op(...)  istream & operator >> (istream &in, __VA_ARGS__ &u)
#define       print_op(...)  ostream & operator << (ostream &out, const __VA_ARGS__ &u)
#ifdef LOCAL
    #include "debug.h"
#else
    #define file(name) if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
    #define DB(...) 23
    #define db(...) 23
    #define debug(...) 23
#endif

template <class U, class V> scan_op(pair <U, V>)  { return in >> u.first >> u.second; }
template <class T> scan_op(vector <T>)  { for (size_t i = 0; i < u.size(); ++i) in >> u[i]; return in; }
template <class U, class V> print_op(pair <U, V>)  { return out << '(' << u.first << ", " << u.second << ')'; }
template <size_t i, class T> ostream & print_tuple_utils(ostream &out, const T &tup) { if constexpr(i == tuple_size<T>::value) return out << ")";  else return print_tuple_utils<i + 1, T>(out << (i ? ", " : "(") << get<i>(tup), tup); }
template <class ...U> print_op(tuple<U...>) { return print_tuple_utils<0, tuple<U...>>(out, u); }
template <class Con, class = decltype(begin(declval<Con>()))> typename enable_if <!is_same<Con, string>::value, ostream&>::type operator << (ostream &out, const Con &con) { out << '{'; for (__typeof(con.begin()) it = con.begin(); it != con.end(); ++it) out << (it == con.begin() ? "" : ", ") << *it; return out << '}'; }

// index from 0
template <class T> struct Fenwick {
    int n; vector <T> bit;
    Fenwick(int _n = 0): n(_n), bit(n + 1, 0) {}
    void reset(void) { fill(bit.begin(), bit.end(), 0); }
    void resize(int _n) { n = _n; bit.assign(n + 1, 0); }
    void update(int i, T val) { for (++i; i <= n; i += i & -i) bit[i] += val; }
    T get(int i) {
        if (i < 0) return 0;
        T res(0);
        for (i = min(i + 1, n); i > 0; i &= i - 1) res += bit[i];
        return res;
    }
    int upper_bound(T val) {
        int res = 0;
        for (int i = __lg(n); i >= 0; --i) 
            if ((res | MASK(i)) <= n && val >= bit[res | MASK(i)]) res |= MASK(i), val -= bit[res];
        return res;
    }
    int lower_bound(T val) {
        int res = 0;
        for (int i = __lg(n); i >= 0; --i)
            if ((res | MASK(i)) <= n && val > bit[res | MASK(i)]) res |= MASK(i), val -= bit[res];
        return res;
    }
};

// end of template

void process(void) {
	int n, q; cin >> n >> q;
	vector <int> p(n); cin >> p;
	vector <int> nxt(n), left(n);
	REPD(i, n) {
		--p[i];
		nxt[i] = i + 1;
		while (nxt[i] < n && p[i] > p[nxt[i]]) nxt[i] = nxt[nxt[i]];
		left[p[i]] = i;
	}
	priority_queue <int> pq;
	vector <int> right(n);
	Fenwick <int> bit(n);
	for (int i = 0; i < n; i = nxt[i]) {
		right[p[i]] = nxt[i];
		bit.update(p[i], nxt[i] - i);
		if (i < n / 2) pq.push(p[i]);
	}
	int sz = right[pq.top()];
	vector <vector <pair <int, int>>> queriesAt(n + 1);
	REP(i, q) {
		int t, x; cin >> t >> x;
		queriesAt[min(t, n)].emplace_back(x - 1, i);
	}
	vector <int> res(q);
	REP(t, n + 1) {
		for (auto [x, i]: queriesAt[t]) {
			int k = bit.upper_bound(x);
			res[i] = p[left[k] + x - bit.get(k - 1)]; 
		}
		int v = pq.top();
		int r = right[v];
		right[v] -= sz - n / 2;
		bit.update(v, n / 2 - sz);
		for (int i = right[v]; i < r; i = nxt[i]) {
			pq.push(p[i]);
			right[p[i]] = min(r, nxt[i]);
			bit.update(p[i], right[p[i]] - i);
		}
		while (true) {
			int v = pq.top();
			int l = left[v];
			int r = right[v];
			if (sz - r + l >= n / 2) {
				pq.pop();
				sz -= r - l;
			} else break;
		}
	}
	REP(i, q) cout << res[i] + 1 << '\n';
}

int main(void) {
	ios_base::sync_with_stdio(false); cin.tie(nullptr); // cout.tie(nullptr);
	file("abracadabra");
	// int t; cin >> t; while (t--)
	process();
	// cerr << "Time elapsed: " << TIME << " s.\n";
	return (0^0);
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:30:61: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   30 |     #define file(name) if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
      |                                                      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:126:2: note: in expansion of macro 'file'
  126 |  file("abracadabra");
      |  ^~~~
Main.cpp:30:94: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   30 |     #define file(name) if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
      |                                                                                       ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:126:2: note: in expansion of macro 'file'
  126 |  file("abracadabra");
      |  ^~~~

• Subtask 1: 10 / 10
• Subtask 2: 40 / 40
• Subtask 3: 25 / 25
• Subtask 4: 25 / 25