Submission #1039037

#	Time	Username	Problem	Language	Result	Execution time	Memory
1039037		TrinhKhanhDung	Hacker (BOI15_hac)	C++14	100 / 100	47 ms	23488 KiB

hac

#include <bits/stdc++.h>
#define ll long long
#define fi first
#define se second
#define sz(x) (int)x.size()
#define ALL(v) v.begin(),v.end()
#define MASK(k) (1LL << (k))
#define BIT(x, i) (((x) >> (i)) & 1)
#define oo (ll)1e18
#define INF (ll)1e9
#define MOD (ll)(1e9 + 7)

using namespace std;

template<class T1, class T2>
    bool maximize(T1 &a, T2 b){if(a < b){a = b; return true;} return false;}

template<class T1, class T2>
    bool minimize(T1 &a, T2 b){if(a > b){a = b; return true;} return false;}

template<class T1, class T2>
    void add(T1 &a, T2 b){a += b; if(a >= MOD) a -= MOD;}

template<class T1, class T2>
    void sub(T1 &a, T2 b){a -= b; if(a < 0) a += MOD;}

template<class T>
    void cps(T &v){sort(ALL(v)); v.resize(unique(ALL(v)) - v.begin());}

void solve(){
    int n; cin >> n;
    vector<int> a;
    for(int i=0; i<n; i++){
        int u; cin >> u;
        a.push_back(u);
    }
    for(int i=0; i<n; i++){
        a.push_back(a[i]);
    }
    ll k = n - n / 2, ans = 0;
    vector<ll> pre(2 * n + 3, 0), p(2 * n + 3, 0);
    for(int i=1; i<=2*n; i++){
        pre[i] = pre[i - 1] + a[i - 1];
        if(i >= k) p[i] = pre[i] - pre[i - k];
//        cout << p[i] << ' ';
    }

    deque<int> dq;
    for(int i=2*n; i>=k; i--){
        if(sz(dq) && dq.front() - i >= k) dq.pop_front();
        while(sz(dq) && p[dq.back()] > p[i]) dq.pop_back();
        dq.push_back(i);
        if(i + k - 1 <= n*2){
            maximize(ans, p[dq.front()]);
        }
    }
    cout << ans << '\n';
}

signed main(){
    ios_base::sync_with_stdio(0); cin.tie(0);
//    freopen("task.inp", "r", stdin);
//    freopen("task.out", "w", stdout);

    int t = 1;
//    cin >> t;
    while(t--){
        solve();
    }

    return 0;
}

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