Submission #1017824

#	Time	Username	Problem	Language	Result	Execution time	Memory
1017824		vjudge1	Feast (NOI19_feast)	C++17	100 / 100	177 ms	15188 KiB

feast

#include<bits/stdc++.h>
using namespace std;
#define int long long
#define ld long double
#define endl '\n'
#define FF first
#define SS second
#define all(a) a.begin(), a.end()
#define mod (ll)(1000000007)

signed main() {
    ios_base::sync_with_stdio(0);cin.tie(0);

    int n, k;
    cin >> n >> k;

    vector<int> A(n + 1);
    for (int i = 1; i <= n; i++) {
        cin >> A[i];
    }
    int l = 0, r = 1e18, res = 0;
    while (l <= r) {
        int md = (l + r) / 2;

        vector<array<array<int, 2>, 2>> dp(n + 1);
        dp[0][1][0] = -md, dp[0][1][1] = 1;
        for (int i = 1; i <= n; i++) {
            dp[i][1][0] = -md, dp[i][1][1] = 1;
            if (dp[i - 1][0][0] - md + A[i] > dp[i][1][0]) {
                dp[i][1][0] = dp[i - 1][0][0] - md + A[i];
                dp[i][1][1] = dp[i - 1][0][1] + 1;
            }
            if (dp[i - 1][1][0] + A[i] > dp[i][1][0]) {
                dp[i][1][0] = dp[i - 1][1][0] + A[i];
                dp[i][1][1] = dp[i - 1][1][1];
            }
            if (dp[i - 1][0][0] > dp[i][0][0]) {
                dp[i][0][0] = dp[i - 1][0][0];
                dp[i][0][1] = dp[i - 1][0][1];
            }
            if (dp[i - 1][1][0] > dp[i][0][0]) {
                dp[i][0][0] = dp[i - 1][1][0];
                dp[i][0][1] = dp[i - 1][1][1];
            }
        }

        if (dp.back()[0][0] < dp.back()[1][0]) {
            swap(dp.back()[0], dp.back()[1]);
        }

        if (dp.back()[0][1] <= k) {
            r = md - 1, res = max(res, dp.back()[0][0] + md * dp.back()[0][1]);
        }
        else if (dp.back()[0][1] > k){
            l = md + 1;
        }

    }
    cout << res;
}

• 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