Submission #857621

#	Time	Username	Problem	Language	Result	Execution time	Memory
857621		hungnt	Feast (NOI19_feast)	C++17	45 / 100	81 ms	132920 KiB

feast

#include<bits/stdc++.h>
using namespace std;

const int N = 300005;

int n, k;
int a[N];
long long dp[2003][2003][2];

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    cin >> n >> k;
    int cntam = 0;
    long long s = 0;
    for(int i = 1; i <= n; i++)
    {
        cin >> a[i];
        cntam += (a[i] < 0);
        s += a[i];
    }
    if(!cntam)
    {
        cout << s;
        return 0;
    }
    if(cntam == 1)
    {
        long long l = 0, r = 0;
        int id = 1;
        while(a[id] >= 0)
        {
            l += id;
            id++;
        }
        id = n;
        while(a[id] >= 0)
        {
            r += id;
            id--;
        }
        if(k == 1) cout << max({l, r, s});
        else cout << l + r;
        return 0;
    }
    long long ans=0;
    dp[0][0][1] = 0;
    dp[0][0][0] = 0;
    for(int i = 1; i <= n; i++)
    {
        dp[i][0][0] = 0;
        for(int j = 1; j <= k; j++)
        {
            dp[i][j][0] = max(dp[i - 1][j][1], dp[i - 1][j][0]);
            dp[i][j][1] = max(dp[i - 1][j][1], dp[i - 1][j - 1][0]) + a[i];
			ans = max({ans, dp[i][j][0], dp[i][j][1]});
        }
    }
    cout << ans;
    return 0;
}

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