Submission #305053

#	Time	Username	Problem	Language	Result	Execution time	Memory
305053		luciocf	Feast (NOI19_feast)	C++14	59 / 100	146 ms	8576 KiB

feast

#include <bits/stdc++.h>

#define ff first
#define ss second

using namespace std;

typedef long long ll;
typedef pair<ll, int> pii;

const int maxn = 3e5+10;
const ll inf = 1e13+10;

int n;
int a[maxn];

ll pref[maxn];

pii dp[maxn];

int qtd(ll c)
{
	memset(dp, 0, sizeof dp);
	
	pii mx = {0, 0};

	for (int i = 1; i <= n; i++)
	{
		mx = max(mx, {dp[i-1].ff - pref[i-1], dp[i-1].ss});

		dp[i] = max(dp[i-1], {pref[i] + mx.ff + c, mx.ss+1});
	}

	return dp[n].ss;
}

int main(void)
{
	int k;
	scanf("%d %d", &n, &k);

	for (int i = 1; i <= n; i++)
	{
		scanf("%d", &a[i]);

		pref[i] = pref[i-1]+1ll*a[i];
	}

	ll ini = -inf, fim = 0, best = -inf;

	while (ini <= fim)
	{
		ll mid = (ini+fim)/2ll;

		if (qtd(mid) > k) fim = mid-1;
		else best = mid, ini = mid+1;
	}

	qtd(best);

	printf("%lld\n", dp[n].ff - 1ll*k*best);
}

Compilation message (stderr)

feast.cpp: In function 'int main()':
feast.cpp:40:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   40 |  scanf("%d %d", &n, &k);
      |  ~~~~~^~~~~~~~~~~~~~~~~
feast.cpp:44:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   44 |   scanf("%d", &a[i]);
      |   ~~~~~^~~~~~~~~~~~~

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