Submission #1143494

#	Time	Username	Problem	Language	Result	Execution time	Memory
1143494		dpsaveslives	Hacker (BOI15_hac)	C++20	100 / 100	224 ms	16092 KiB

hac

#include <bits/stdc++.h>
using namespace std;
const int MAXN = 5e5+5;
int arr[MAXN],pref[MAXN];
int main()
{
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    int N; cin >> N;
    for(int i = 1;i<=N;++i){
        cin >> arr[i];
        pref[i] = pref[i-1]+arr[i];
    }
    int len = (N+1)/2, ans = 0;
    multiset<int> ms;
    for(int i = 1;i<=len-1;++i){
        ms.insert(pref[i]+pref[N]-pref[N-(len-i)]);
    }
    for(int i = 1;i<=N;++i){
        if(i != 1){
            if(i-len-1 >= 0){
                ms.erase(ms.find(pref[i-1]-pref[i-len-1]));
            }
            else{
                ms.erase(ms.find(pref[i-1]+pref[N]-pref[N-(len-(i-1))]));
            }
        }
        if(i+len-1 <= N){
            ms.insert(pref[i+len-1]-pref[i-1]);
            //cout << pref[i+len-1]-pref[i-1] << "\n";
        }
        else{
            ms.insert(pref[N]-pref[i-1]+pref[len-(N-i+1)]);
            //cout << pref[N]-pref[i-1]+pref[len-(N-i+1)] << "\n";
        }
        ans = max(ans,(*ms.begin()));
    }
    cout << ans << "\n";
    return 0;
}

• Subtask 1: 20 / 20
• Subtask 2: 20 / 20
• Subtask 3: 20 / 20
• Subtask 4: 40 / 40