Submission #950591

#	Time	Username	Problem	Language	Result	Execution time	Memory
950591		VMaksimoski008	Feast (NOI19_feast)	C++14	63 / 100	99 ms	25948 KiB

feast

#include <bits/stdc++.h>

#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define int long long

using namespace std;

using ll = long long;
using ull = unsigned long long;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;

const int mod = 1e9 + 7;
const int LOG = 20;
const int maxn = 1e5 + 5;
const double eps = 1e-9;

int32_t main() {
    int n, K, neg = 0;
    cin >> n >> K;

    vector<int> v(n+1);
    vector<ll> pref(n+1);
    for(int i=1; i<=n; i++) {
        cin >> v[i];
        neg += (v[i] < 0);
        pref[i] = pref[i-1] + v[i];
    }

    if(neg == 0) {
        cout << pref[n] << '\n';
        return 0;
    }

    if(neg == 1) {
        ll ans1=0, ans2=0, N=0;
        for(int i=1; i<=n; i++) if(v[i] < 0) N = v[i];

        for(int i=1; i<=N; i++) {
            if(v[i] < 0) break;
            ans1 += v[i];
        }

        for(int i=N; i>=1; i--) {
            if(v[i] < 0) break;
            ans2 += v[i];
        }

        if(K >= 2) cout << pref[n] - N << '\n';
        else cout << max({ ans1, ans2, pref[n] }) << '\n';
        return 0;
    }

    if(K == 1) {
        ll ans = 0, sum = 0, mn = 0;

        for(int i=1; i<=n; i++) {
            sum += v[i];
            ans = max(ans, sum - mn);
            mn = min(mn, sum);
        }

        cout << ans << '\n';
        return 0;
    }

    ll dp[n+1][K+1], mx[K+1];
    memset(dp, 0, sizeof(dp));
    memset(mx, 0, sizeof(mx));
 
    for(int i=1; i<=n; i++) {
        for(int j=0; j<=K; j++) {
            dp[i][j] = dp[i-1][j];
            if(j) dp[i][j] = max(dp[i][j], pref[i] + mx[j-1]);
        }

        for(int j=0; j<=K; j++) mx[j] = max(mx[j], dp[i][j] - pref[i]);
    }
 
    cout << dp[n][K] << '\n';
    return 0;
}

• Subtask 1: 4 / 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