Submission #902475

#	Time	Username	Problem	Language	Result	Execution time	Memory
902475		thinknoexit	Feast (NOI19_feast)	C++17	100 / 100	122 ms	10536 KiB

feast

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int a[300300], n;
ll qs[300300];
ll dp[300300];
int cnt[300300];
void cal(ll mid) {
    pair<ll, int> mx(0ll, 0);
    for (int i = 1;i <= n;i++) {
        dp[i] = dp[i - 1];
        cnt[i] = cnt[i - 1];
        if (qs[i] + mx.first - mid > dp[i]) {
            dp[i] = qs[i] + mx.first - mid;
            cnt[i] = mx.second + 1;
        }
        mx = max(mx, { dp[i] - qs[i], cnt[i] });
    }
}
int main() {
    cin.tie(nullptr)->sync_with_stdio(false);
    int k;
    cin >> n >> k;
    for (int i = 1;i <= n;i++) {
        cin >> a[i];
        qs[i] = qs[i - 1] + a[i];
    }
    ll l = 0, r = 1e13;
    while (l < r) {
        ll mid = l + (r - l) / 2;
        cal(mid);
        if (cnt[n] <= k) r = mid;
        else l = mid + 1;
    }
    cal(l);
    cout << dp[n] + l * cnt[n];
    return 0;
}

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