Submission #708026

#	Time	Username	Problem	Language	Result	Execution time	Memory
708026		Johann	Uplifting Excursion (BOI22_vault)	C++14	0 / 100	2 ms	596 KiB

vault

#include "bits/stdc++.h"
using namespace std;

typedef long long ll;
typedef pair<ll, ll> pii;
typedef vector<pii> vpii;
typedef vector<ll> vi;
#define sz(x) (int)(x).size()
#define all(x) (x).begin(), (x).end()

void resetPQ(priority_queue<pii, vpii> &q, int cut)
{
    priority_queue<pii, vpii> qq;
    while (!q.empty())
    {
        pii tmp = q.top();
        q.pop();
        if (tmp.second >= cut)
            qq.push(tmp);
    }
    swap(q, qq);
}

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

    ll M, L;
    cin >> M >> L;
    vi A(2 * M + 1);
    for (int i = 0; i < sz(A); ++i)
        cin >> A[i];

    int MAXSIZE = accumulate(all(A), 0LL) * M;

    vi dp(MAXSIZE, -1);
    ll center = MAXSIZE / 2;
    dp[center] = A[M];
    for (int foo = 0; foo < 2; ++foo)
    {
        reverse(all(A)), reverse(all(dp));
        for (ll m = 1; m <= M; ++m)
        {
            ll maxNum = A[m + M];
            for (ll r = 0; r < m; ++r)
            {
                priority_queue<pii, vpii> q;
                for (int i = 0; m * i + r < sz(dp); ++i)
                {
                    int idx = m * i + r;
                    while (!q.empty() && q.top().second < idx - maxNum * m)
                        q.pop();
                    if (sz(q) > 2 * m)
                        resetPQ(q, idx - maxNum * m);
                    if (dp[idx] != -1)
                        q.push({dp[idx] - i, idx});
                    if (!q.empty())
                        dp[idx] = i + q.top().first;
                }
            }
        }
    }

    ll ans = -1;
    if (0 <= center + L && center + L < sz(dp))
        ans = dp[center + L];
    if (ans == -1)
        cout << "impossible\n";
    else
        cout << ans << "\n";

    return 0;
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 15
• Subtask 3-1: 0 / 10
• Subtask 3-2: 0 / 10
• Subtask 4-1: 0 / 10
• Subtask 4-2: 0 / 10
• Subtask 5-1: 0 / 10
• Subtask 5-2: 0 / 10
• Subtask 6-1: 0 / 10
• Subtask 6-2: 0 / 10