Submission #1298681

#	Time	Username	Problem	Language	Result	Execution time	Memory
1298681		nathlol2	Feast (NOI19_feast)	C++20	18 / 100	75 ms	12156 KiB

feast

#include <bits/stdc++.h>
#define int long long
using namespace std;
const int N = 333333;
int n, k, a[N];
pair<int, int> dp[N][2];
pair<int, int> solve(int x){
    dp[1][0] = {0, 0};
    dp[1][1] = {a[1] - x, 1};
    for(int i = 2;i<=n;i++){
        dp[i][0] = dp[i][1] = {-4e18, 0};
        dp[i][0] = max(dp[i - 1][0], dp[i - 1][1]);
        dp[i][1] = max(make_pair(dp[i - 1][1].first + a[i], dp[i - 1][1].second), make_pair(dp[i - 1][0].first + a[i] - x, dp[i - 1][0].second + 1));
    }
    return max(dp[n][0], dp[n][1]);
}

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

    cin >> n >> k;
    for(int i = 1;i<=n;i++) cin >> a[i];
    int l = 0, r = 1e18, ans = -1;
    while(l <= r){
        int md = (l + r) / 2;
        if(solve(md).second >= k){
            ans = md;
            l = md + 1;
        }else{
            r = md - 1;
        }
    }
    cout << solve(ans).first + k * ans;
}

• Subtask 1: 0 / 4
• Subtask 2: 0 / 8
• Subtask 3: 18 / 18
• Subtask 4: 0 / 10
• Subtask 5: 0 / 11
• Subtask 6: 0 / 20
• Subtask 7: 0 / 29