Submission #1025728

#	Time	Username	Problem	Language	Result	Execution time	Memory
1025728		Gr1sen	Feast (NOI19_feast)	C++17	100 / 100	125 ms	15188 KiB

feast

#include<iostream>
#include<vector>
#include<iomanip>
#include<algorithm>

using namespace std;

#define ll long long
#define ld long double
#define vi vector<ll>
#define vvi vector<vi>
#define pi pair<ll, ll>
#define ppi pair<ll, pi>
#define vp vector<ppi>
#define vvp vector<vp>
#define MP make_pair

ll n, k;
vi L;

pi oink(ll c) {
    pi dp[n][2];

    dp[0][0] = {0, 0};
    dp[0][1] = {L[0] - c, 1};
    for (int i = 1; i < n; i++) {
        dp[i][0] = max(dp[i-1][0], dp[i-1][1]);

        dp[i][1] = max(MP(dp[i-1][1].first + L[i], dp[i-1][1].second), MP(dp[i-1][0].first + L[i] - c, dp[i-1][0].second + 1));
    }
    return max(dp[n-1][0], dp[n-1][1]);
}

int main() {
    ios::sync_with_stdio(0); cin.tie(0);
    cin >> n >> k;
    L = vi(n);
    for (auto &i : L) cin >> i;

    ll l = 0, r = 1e18;
    ll ans = 0;
    while (l < r) {
        //cerr << l << " " << r << endl;
        ll m = (l+r)/2;
        pi a = oink(m);
        if (a.second == k) {
            ans = a.first + m*k;
            break;
        }
        if (a.second > k) {
            l = m+1;
            continue;
        }
        ans = a.first + a.second*m;
        r = m;
    }
    cout << ans << "\n";
}

/*
6 1
1 -2 3 -1 5 -6

6 2
1 2 3 -10 5 6

6 4
-1 -2 -1 0 -5 -1
*/

• 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