Submission #785383

#	Time	Username	Problem	Language	Result	Execution time	Memory
785383		acatmeowmeow	Split the sequence (APIO14_sequence)	C++11	0 / 100	5 ms	1108 KiB

sequence

#include <bits/stdc++.h>

using namespace std;

#define int long long 

const int N = 1e5;
int n, K, prefix[N + 5];
set<tuple<int, int, int, int>, greater<tuple<int, int, int, int>>> segment;

signed main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	cin >> n >> K;
	for (int i = 1;i <= n; i++) {
		int x;
		cin >> x;
		prefix[i] = prefix[i - 1] + x;
	}
	int index = 1, cur = 0;
	for (int i = 1; i < n; i++) index = cur < prefix[i]*(prefix[n] - prefix[i]) ? i : index, cur = max(cur, prefix[i]*(prefix[n] - prefix[i]));
	segment.insert({cur, 1, n, index});
	int ans = 0;
	while (K) {
		K--;
		auto x = *segment.begin();
		segment.erase(segment.begin());
		int v = get<0>(x), a = get<1>(x), b = get<2>(x), m = get<3>(x);
		ans += v;
		if (a == b) continue;

		int index = a, cur = 0;
		for (int i = a; i <= m; i++) {
			int res = (prefix[i] - prefix[a - 1])*(prefix[m] - prefix[i]);
			if (cur < res) cur = res, index = i;
		}
		segment.insert({cur, a, m, index});

		index = m + 1, cur = 0;
		for (int i = m + 1; i <= b; i++) {
			int res = (prefix[i] - prefix[m])*(prefix[b] - prefix[i]);
			if (cur < res) cur = res, index = i;
		}
		segment.insert({cur, m + 1, b, index});
		
	}
	cout << ans << '\n';
	return 0;
}

• Subtask 1: 0 / 11
• Subtask 2: 0 / 11
• Subtask 3: 0 / 11
• Subtask 4: 0 / 17
• Subtask 5: 0 / 21
• Subtask 6: 0 / 29