Submission #947362

#	Time	Username	Problem	Language	Result	Execution time	Memory
947362		SirCovidThe19th	Feast (NOI19_feast)	C++17	100 / 100	258 ms	12964 KiB

feast

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

const int MAX = 300000;
const ll INF = (ll)300000 * 1000000000;

int n, k, A[MAX + 1]; 
pair<ll, ll> dp[MAX + 1][2];
 
pair<ll, ll> better(pair<ll, ll> a, pair<ll, ll> b){
    if (a.first == b.first){ return (a.second < b.second ? a : b); }

    return (a.first > b.first ? a : b);
}

pair<ll, ll> solveLambda(ll lmb){
    dp[0][0] = {0, 0}; 
    dp[0][1] = {-INF, 0};
 
    for (int i = 1; i <= n; i++){
        dp[i][0] = better(dp[i - 1][0], dp[i - 1][1]);

        dp[i][1] = better(
            {dp[i - 1][0].first + A[i] - lmb, dp[i - 1][0].second + 1}, 
            {dp[i - 1][1].first + A[i], dp[i - 1][1].second}
        );
    }
    return better(dp[n][0], dp[n][1]);
}
 
int main(){
    cin >> n >> k;

    for (int i = 1; i <= n; i++) cin >> A[i];
 
    ll lo = 0, hi = 1e15;

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