Submission #951973

#	Time	Username	Problem	Language	Result	Execution time	Memory
951973		SirCovidThe19th	Feast (NOI19_feast)	C++17	100 / 100	226 ms	13992 KiB

feast

#include <bits/stdc++.h>
using namespace std;

#define ll long long

int main(){
    int n, k;
    cin >> n >> k;

    int a[n];
    for (int &i : a) cin >> i;

    auto solveLambda = [&](ll lmb){
        pair<ll, ll> dp[n][2];

        dp[0][0] = {0, 0}; 
        dp[0][1] = {a[0] - lmb, 1};
    
        for (int i = 1; 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] - lmb, dp[i - 1][0].second + 1), 
                make_pair(dp[i - 1][1].first + a[i], dp[i - 1][1].second)
            );
        }
        return max(dp[n - 1][0], dp[n - 1][1]);
    };
    
    ll lo = 0, hi = 1e18;

    while (lo < hi){
        ll mid = (lo + hi) / 2;
        solveLambda(mid).second <= k ? hi = mid : lo = mid + 1;
    }    
    cout << solveLambda(lo).first + lo * k << endl;
}

• 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