Submission #376865

#	Time	Username	Problem	Language	Result	Execution time	Memory
376865		8e7	Cake 3 (JOI19_cake3)	C++14	24 / 100	4056 ms	13000 KiB

cake3

//Challenge: Accepted
#include <iostream>
#include <algorithm>
#include <vector>
#include <utility>
#include <queue>
#include <set>
#define ll long long
#define maxn 200005
#define pii pair<int, int>
#define ff first
#define ss second
#define io ios_base::sync_with_stdio(0);cin.tie(0);
using namespace std;

int n, m;

pii a[maxn];
inline bool cmp(pii a, pii b) {
	return a.ss < b.ss;
}
multiset<int> small, big;
ll sum = 0;


inline void add(int ind) {
	sum += a[ind].ff;
	big.insert(a[ind].ff);
	//cout << 1 << "  " << a[ind].ff << endl;
	//cout << sum << endl;
	if (big.size() > m) {
		int ch = *big.begin();
		big.erase(big.begin());
		sum -= ch;
		//cout << 0 << "  " << ch << endl;
		//cout << sum << endl;
		small.insert(ch);
	}
}
inline void rem(int ind) {
	multiset<int>::iterator it = small.find(a[ind].ff);
	if (it != small.end()) {
		//cout << "erase " << *it << endl;
		small.erase(it);
	} else {
		sum -= a[ind].ff;
		//cout << "erase " << 0 << "  " << a[ind].ff << endl;
		big.erase(big.find(a[ind].ff));
		if (big.size() < m) {
			int ch = *prev(small.end());
			small.erase(prev(small.end()));
			sum += ch;
			//cout << 1 << "  " << ch << endl;
			big.insert(ch);
		}
	}
}
int curl = 0, curr = 0;

inline void ins(int l, int r) {
	while (curl > l) curl--, add(curl);
	while (curr < r) add(curr), curr++;
	while (curl < l) rem(curl), curl++;
	while (curr > r) curr--, rem(curr);
}

ll ans = -(1LL<<60);
void solve(int l, int r, int ql, int qr) {
	if (r <= l || qr <= ql) return;
	if (qr - ql == 1) {
		for (int i = l;i < r;i++) {
			ins(ql, i + 1);
			ans = max(ans, sum - 2 * (a[i].ss - a[ql].ss));
		}
		return;
	}
	int mid = (l + r) / 2;
	ll best = -(1LL<<60), bind = 0;

	for (int i = min(qr - 1, mid - m + 1);i >= ql;i--) {
		ins(i, mid + 1);
		ll val = sum - 2 * (a[mid].ss - a[i].ss);
		if (val > best) {
			best = val;
			bind = i;
		}
	}
	ans = max(ans, best);
	solve(l, mid, ql, bind + 1);
	solve(mid + 1, r, bind, qr);
}
int main() {
	io
	cin >> n >> m;
	for (int i = 0;i < n;i++) cin >> a[i].ff >> a[i].ss;
	sort(a, a + n, cmp);
	for (int i = 0;i < m;i++) {
		add(i);
	}
	curr = m;

	solve(m - 1, n, 0, n);
	cout << ans << "\n";

}
/*
5 3
2 1
4 2
6 4
8 8
10 16

8 4
112103441 501365808
659752417 137957977
86280801 257419447
902409188 565237611
965602301 689654312
104535476 646977261
945132881 114821749
198700181 915994879

 */

Compilation message (stderr)

cake3.cpp: In function 'void add(int)':
cake3.cpp:31:17: warning: comparison of integer expressions of different signedness: 'std::multiset<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   31 |  if (big.size() > m) {
      |      ~~~~~~~~~~~^~~
cake3.cpp: In function 'void rem(int)':
cake3.cpp:49:18: warning: comparison of integer expressions of different signedness: 'std::multiset<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   49 |   if (big.size() < m) {
      |       ~~~~~~~~~~~^~~

• Subtask 1: 5 / 5
• Subtask 2: 19 / 19
• Subtask 3: 0 / 76