Submission #1300883

#	Time	Username	Problem	Language	Result	Execution time	Memory
1300883		PakinDioxide	Feast (NOI19_feast)	C++17	100 / 100	135 ms	12164 KiB

feast

#include <bits/stdc++.h>
#define ll long long

using namespace std;

const int mxN = 3e5+5;

int n, k;
ll a[mxN];

int main() {
    ios::sync_with_stdio(0), cin.tie(0);
    cin >> n >> k;
    for (int i = 1; i <= n; i++) cin >> a[i];
    auto solve = [&] (ll ld) {
        pair <ll, ll> dp[n+1][2];
        dp[1][0] = make_pair(0, 0);
        dp[1][1] = make_pair(a[1] - ld, 1);
        for (int i = 2; i <= n; i++) {
            dp[i][0] = max(dp[i-1][0], dp[i-1][1]);
            dp[i][1] = max(make_pair(dp[i-1][0].first + a[i] - ld, dp[i-1][0].second + 1), make_pair(dp[i-1][1].first + a[i], dp[i-1][1].second));
        }
        return max(dp[n][0], dp[n][1]);
    };
    ll L = 0, R = 1e18, ans = 0;
    while (L <= R) {
        ll ld = L + (R-L)/2;
        pair <ll, ll> v = solve(ld);
        if (v.second >= k) ans = ld, L = ld+1;
        else R = ld-1;
    }
    cout << solve(ans).first + ans * k << '\n';
}

• 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