Submission #968973

#	Time	Username	Problem	Language	Result	Execution time	Memory
968973		marvinthang	Diversity (CEOI21_diversity)	C++17	100 / 100	1174 ms	7684 KiB

diversity

/*************************************
*    author: marvinthang             *
*    created: 24.04.2024 16:30:43    *
*************************************/

#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 << '}'; }

// end of template

const int BLOCK_SIZE = 450;

struct Query {
	int l, r, id;
	Query(int l, int r, int id): l(l), r(r), id(id) {}
	bool operator < (const Query &ot) { return pair{l / BLOCK_SIZE, r} < pair{ot.l / BLOCK_SIZE, ot.r}; }
};

void process(void) {
	int n, q; cin >> n >> q;
	vector <int> a(n); cin >> a;
	vector <int> c(ALL(a));
	sort(ALL(c)); c.erase(unique(ALL(c)), c.end());
	REP(i, n) a[i] = lower_bound(ALL(c), a[i]) - c.begin();
	vector <int> cnt(c.size());
	REP(i, n) ++cnt[a[i]];
	vector <int> big;
	REP(i, c.size()) if (cnt[i] >= BLOCK_SIZE) big.push_back(i);
	vector <Query> queries;
	REP(i, q) {
		int l, r; cin >> l >> r; --l; --r;
		queries.emplace_back(l, r, i);
	}
	sort(ALL(queries));
	fill(ALL(cnt), 0);
	vector <int> cnt_cnt(n + 1);
	cnt_cnt[0] = c.size();
	auto add = [&] (int u, int v) {
		--cnt_cnt[cnt[u]];
		cnt[u] += v;
		++cnt_cnt[cnt[u]];
	};
	int cl = 0, cr = -1;
	vector <long long> res(q);
	for (auto [l, r, i]: queries) {
		while (cl > l) add(a[--cl], +1);
		while (cr < r) add(a[++cr], +1);
		while (cl < l) add(a[cl++], -1);
		while (cr > r) add(a[cr--], -1);
		vector <pair <int, int>> left, right;
		int n = 0;
		FOR(i, 1, min((int) cnt_cnt.size() + 1, BLOCK_SIZE)) if (cnt_cnt[i]) {
			if (n & 1) {
				right.emplace_back(i, (cnt_cnt[i] + 1) / 2);
				if (cnt_cnt[i] > 1) left.emplace_back(i, cnt_cnt[i] / 2);
			} else {
				left.emplace_back(i, (cnt_cnt[i] + 1) / 2);
				if (cnt_cnt[i] > 1) right.emplace_back(i, cnt_cnt[i] / 2);
			}
			n += cnt_cnt[i];
		}
		vector <int> v;
		for (int i: big) if (cnt[i] >= BLOCK_SIZE) v.push_back(cnt[i]);
		sort(ALL(v));
		for (int c: v) (++n & 1 ? left : right).emplace_back(c, 1);
		left.insert(left.end(), right.rbegin(), right.rend());
		n = r - l + 1;
		int pref = 0;
		for (auto [c, f]: left) {
			res[i] += 1LL * f * (1LL * c * (c + 1) / 2 + 1LL * c * (n - c));
			res[i] += 1LL * (n - c) * (1LL * pref * f + 1LL * f * (f - 1) / 2 * c);
			res[i] -= 1LL * pref * pref * f + 1LL * pref * f * (f - 1) * c + 1LL * c * c * (f - 1) * f * (f + f - 1) / 6;
			pref += c * f;
		}
	}
	REP(i, q) cout << res[i] << '\n';
}

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

Compilation message (stderr)

diversity.cpp: In function 'int main()':
diversity.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); }
      |                                                      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
diversity.cpp:115:2: note: in expansion of macro 'file'
  115 |  file("diversity");
      |  ^~~~
diversity.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); }
      |                                                                                       ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
diversity.cpp:115:2: note: in expansion of macro 'file'
  115 |  file("diversity");
      |  ^~~~

• Subtask 1: 4 / 4
• Subtask 2: 10 / 10
• Subtask 3: 8 / 8
• Subtask 4: 16 / 16
• Subtask 5: 26 / 26
• Subtask 6: 36 / 36