제출 #1309720

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1309720		aaaaaaaa	Feast (NOI19_feast)	C++20	100 / 100	931 ms	23948 KiB

feast

#include <bits/stdc++.h>
using namespace std;
#define int long long
signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(nullptr); cout.tie(nullptr);
    int n, k;
    cin >> n >> k;
    vector<int> a(n + 1, 0);
    for(int i = 1; i <= n; ++i){
        cin >> a[i];
    }
    auto combine = [&](const pair<int, int> &left, const pair<int, int> &right) -> pair<int, int> {
        return {left.first + right.first, left.second + right.second};
    };
    auto f = [&](int x) -> pair<int, int> {
        vector<vector<pair<int, int>>> dp(n + 1, vector<pair<int, int>> (2, {0, 0}));
        dp[1][1] = {a[1] - x, 1};
        for(int i = 2; i <= n; ++i){
            dp[i][0] = max(dp[i - 1][0], dp[i - 1][1]);
            dp[i][1] = max(combine(dp[i - 1][1], {a[i], 0}), 
                            combine(dp[i - 1][0], {a[i] - x, 1}));
        }
        return max(dp[n][0], dp[n][1]);
    };
    int st = 0, en = 1e18, ans = 0;
    while(st <= en){
        int mid = st + (en - st) / 2;
        if(f(mid).second >= k){
            ans = mid;
            st = mid + 1;
        }else{
            en = mid - 1;
        }
    }
    auto [x, y] = f(ans);
    cout << x + k * ans << "\n";
    return 0;
}   

• 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