Submission #440032

#	Time	Username	Problem	Language	Result	Execution time	Memory
440032		CodeChamp_SS	Hacker (BOI15_hac)	C++17	0 / 100	9 ms	15948 KiB

hac

#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace __gnu_pbds;
using namespace std;

#define ff                  first
#define ss                  second
#define pb                  push_back
#define eb                  emplace_back
#define mp                  make_pair
#define lb                  lower_bound
#define ub                  upper_bound
#define setbits(x)          __builtin_popcountll(x)
#define zrobits(x)          __builtin_ctzll(x)
#define sz(v)               (int)v.size()
#define ps(y)               cout << fixed << setprecision(y)
#define ms(arr, v)          memset(arr, v, sizeof(arr))
#define all(v)              v.begin(), v.end()
#define rall(v)             v.rbegin(), v.rend()
#define trav(x, v)          for(auto &x: v)
#define w(t)                int t; cin >> t; while(t--)
#define rep0(i, n)          for(int i = 0; i < n; i++)
#define rrep0(i, n)         for(int i = n - 1; i >= 0; i--)
#define rep1(i, n)          for(int i = 1; i <= n; i++)
#define rrep1(i, n)         for(int i = n; i > 0; i--)
#define inp(arr, n)         rep0(i, n) cin >> arr[i];
#define rep(i, a, b)        for(int i = a; i <= b; i++)
#define rrep(i, a, b)       for(int i = a; i >= b; i--)

typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<ll, ll> pii;
typedef vector<ll> vi;
typedef vector<vi> vvi;
typedef vector<pii> vp;
typedef vector<bool> vb;
typedef vector<string> vs;
typedef map<ll, ll> mii;
typedef map<char, ll> mci;
typedef priority_queue<ll> pq_mx;
typedef priority_queue<ll, vi, greater<>> pq_mn;
typedef tree<ll, null_type, less<>, rb_tree_tag, tree_order_statistics_node_update> pbds;
/*
 * find_by_order(i) -> returns an iterator to the element at ith position (0 based)
 * order_of_key(i)  -> returns the position of element i (0 based)
 */

const int N = 1e6 + 5;
const int mod = 1e9 + 7;
//const int mod = 998244353;
const ll inf = 1e18;

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

void fio() {
    ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
}

ll n, a[N], fw[N], bk[N];

int main() {
    fio();

    cin >> n;
    inp(a, n)
    rep(x, n, 2 * n - 1) a[x] = a[x - n];

    ms(fw, -1);
    ms(bk, -1);
    ll sum = 0;
    ll k = (n + 1) / 2;
    rep0(x, k) sum += a[x];
    fw[0] = sum;
    rep(x, k, 2 * n - 1) {
        if (fw[(x % n - k + 1 + n) % n] != -1) break;
        sum -= a[x - k], sum += a[x];
        fw[(x % n - k + 1 + n) % n] = sum;
    }

    sum = 0;
    for (int x = 2 * n - 1, i = 0; i < k; x--, i++) sum += a[x];
    bk[n - 1] = sum;
    rrep0(x, 2 * n - k) {
        if (bk[(x % n + k - 1) % n] != -1) break;
        sum -= a[x + k], sum += a[x];
        bk[(x % n + k - 1) % n] = sum;
    }

    ll res = 0;
    rep0(x, n) res = max(res, min(fw[x], bk[x]));
    cout << res;

    return 0;
}

• Subtask 1: 0 / 20
• Subtask 2: 0 / 20
• Subtask 3: 0 / 20
• Subtask 4: 0 / 40