제출 #1084440

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1084440		anhthi	Hacker (BOI15_hac)	C++14	100 / 100	40 ms	15700 KiB

hac

#include <bits/stdc++.h>

using namespace std;

#define fi first
#define se second
#define ll long long
#define mp(x, y) make_pair(x, y)
#define sz(v) ((int) (v).size())
#define all(v) (v).begin(), (v).end()
#define MASK(i) (1LL << (i))
#define BIT(x, y) (((x) >> (y)) & 1)
#define pb push_back
#define max_rng *max_element
#define min_rng *min_element
#define rep(i, n) for(int i = 1, _n = (n); i <= _n; ++i)
#define forn(i, a, b) for(int i = (a), _b = (b); i <= _b; ++i)
#define ford(i, a, b) for(int i = (a), _b = (b); i >= _b; --i)

template <class X, class Y>
    inline bool maximize(X &x, Y y) {
        return (x < y ? x = y, true : false);
    }

template <class X, class Y>
    inline bool minimize(X &x, Y y) {
        return (x > y ? x = y, true : false);
    }

template <class X>
    inline void compress(vector<X> &a) {
        sort(all(a));
        a.resize(unique(all(a)) - a.begin());
    }

int ctz(ll x) { return __builtin_ctzll(x); }
int lg(ll x) { return 63 - __builtin_clzll(x); }
int popcount(ll x) { return __builtin_popcount(x); }

mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rand(ll l, ll r) {
    return l + abs((ll) rng()) % (r - l + 1);
}

const ll oo = (ll) 1e17;
const int inf = (ll) 2e9 + 7, mod = (ll) 1e9 + 7;

const int mxn = 2e6, mxm = 3e6;
const int LG = 18;

int n;
int a[mxn + 5];
int pref[mxn + 5], p[mxn + 5];

int main(void) {

    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

    cin >> n;
    rep(i, n) {
        cin >> a[i];
        a[i + n] = a[i];
    }

    int v = n / 2 + (n & 1);
    rep(i, n << 1) {
        pref[i] = pref[i-1] + a[i];
        p[i] = pref[i] - (i < v ? 0 : pref[i - v]);
    }
    int ans = 0;
    deque<int> dq;
    ford(i, n << 1, 1) {
        while (!dq.empty() && p[i] < p[dq.front()])
            dq.pop_front();
        dq.push_front(i);
        while (dq.back() - i >= v)
            dq.pop_back();

        if (i + v - 1 <= (n << 1))
            maximize(ans, p[dq.back()]);
    }

    cout << ans;

    return 0;
}

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