Submission #1278101

#	Time	Username	Problem	Language	Result	Execution time	Memory
1278101		anarch_y	Hacker (BOI15_hac)	C++20	100 / 100	44 ms	13056 KiB

hac

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define all(x) begin(x), end(x)
#define sz(x) (int)x.size()
#define pb push_back

int main(){
    ios::sync_with_stdio(0);
    cin.tie(0);

    int n; cin >> n;
    vector<int> a(2*n+1);
    for(int i=1; i<=n; i++) cin >> a[i];
    for(int i=n+1; i<=2*n; i++) a[i] = a[i-n];
    vector<int> p(2*n+1);
    for(int i=1; i<=2*n; i++){
        p[i] = a[i] + p[i-1];
    }
    int k = (n+1)/2;
    vector<int> b(2*n+1);
    for(int i=k; i<=2*n; i++){
        b[i] = p[i] - p[i-k];
    }
    for(int i=1; i<k; i++){
        b[i] = b[i+n];
    }
    deque<int> d;
    int ans = 0;
    for(int i=1; i<=k; i++){
        while(!d.empty() and d.back() > b[i]) d.pop_back();
        d.push_back(b[i]);
    }
    ans = max(ans, d.front());
    for(int i=k+1; i<=2*n; i++){
        if(!d.empty() and d.front() == b[i-k]) d.pop_front();
        while(!d.empty() and d.back() > b[i]) d.pop_back();
        d.push_back(b[i]);
        ans = max(ans, d.front());
    }
    cout << ans;
}

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