Submission #1026011

#	Time	Username	Problem	Language	Result	Execution time	Memory
1026011		fv3	Feast (NOI19_feast)	C++17	12 / 100	35 ms	7896 KiB

feast

#include <bits/stdc++.h>

using namespace std;
typedef long long ll;

vector<ll> a, b;

ll res;
ll solve(ll pun)
{
	res = 0;
	ll last = -pun;
	ll seg_cnt = 0;

	for (auto n : b)
	{
		if (n > 0)
			last += n;
		else if (n < -pun)
		{
			res += last;
			if (last > 0)
				seg_cnt++;
			last = -pun;
		}
		else
		{
			last += n;
		}

		if (last < -pun)
			last = -pun;

		//cerr << last << ' ' << res << '\n';
	}

	if (last > 0)
	{
		res += last;
		seg_cnt++;
	}

	return seg_cnt;
}

int main()
{
	ios::sync_with_stdio(0);
	cin.tie(0);

	ll N, K;
	cin >> N >> K;

	a = vector<ll>(N);

	for (int i = 0; i < N; i++)
		cin >> a[i];


	{
		ll sum = a[0];
		for (int i = 1; i < N; i++)
		{
			if ((a[i-1] ^ a[i]) < 0)
			{
				b.push_back(sum);
				sum = 0;
			}
			sum += a[i];
		}

		if (sum != 0)
			b.push_back(sum);
	}

	ll l = 0; 
	ll r = 1e18;

	while (l < r)
	{
		ll c = (l + r) / 2ll;

		if (solve(c) > K)
			l = c + 1;
		else
			r = c;
	}
	ll seg_cnt = solve(l);
	cout << res + K * l << '\n';

	return 0;
}

Compilation message (stderr)

feast.cpp: In function 'int main()':
feast.cpp:88:5: warning: unused variable 'seg_cnt' [-Wunused-variable]
   88 |  ll seg_cnt = solve(l);
      |     ^~~~~~~

• Subtask 1: 4 / 4
• Subtask 2: 8 / 8
• Subtask 3: 0 / 18
• Subtask 4: 0 / 10
• Subtask 5: 0 / 11
• Subtask 6: 0 / 20
• Subtask 7: 0 / 29