Submission #1231366

#	Time	Username	Problem	Language	Result	Execution time	Memory
1231366		omsincoconut	Uplifting Excursion (BOI22_vault)	C++17	0 / 100	175 ms	588 KiB

vault

#include <bits/stdc++.h>

using namespace std;
typedef long long ll;

const ll INF = 1e18, BOUND = 10000;

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    ll M, L;
    cin >> M >> L;

    ll A[2*M+1];
    for (ll i = 0; i <= 2*M; i++) cin >> A[i];

    ll sum = 0, cnt = 0;
    for (ll i = 0; i <= 2*M; i++) sum += (i-M)*A[i], cnt += A[i];

    if (sum < L) {
        cout << "impossible";
        return 0;
    } else if (L == 0) {
        cout << A[0];
        return 0;
    }

    ll idx = -1, take = -1;
    for (ll i = 2*M; i >= M+1; i--) {
        if (sum-(i-M)*A[i] > L) {
            sum -= (i-M)*A[i];
            cnt -= A[i];
        } else {
            idx = i-M;
            take = (sum-L)/(i-M);
            sum -= (i-M)*take;
            cnt -= take;
        }
    }

    ll knap_min[BOUND];
    fill(knap_min, knap_min+BOUND, INF);
    knap_min[0] = 0;
    for (ll i = 1; i < idx; i++) {
        for (ll j = BOUND-1; j >= 0; j--) {
            for (ll k = 1; j-i*k >= 0 && k <= A[M+i]; k++) {
                knap_min[j] = min(knap_min[j], knap_min[j-i*k]+k);
            }
        }
    }

    for (ll j = BOUND-1; j >= 0; j--) {
        for (ll k = 1; j-idx*k >= 0 && k <= A[M+idx]-take; k++) {
            knap_min[j] = min(knap_min[j], knap_min[j-idx*k]+k);
        }
    }

    ll knap_max[BOUND];
    fill(knap_max, knap_max+BOUND, -INF);
    knap_max[0] = 0;
    for (ll i = idx+1; i <= M; i++) {
        for (ll j = BOUND-1; j >= 0; j--) {
            for (ll k = 1; j-i*k >= 0 && k <= A[M+i]; k++) {
                knap_max[j] = max(knap_max[j], knap_max[j-i*k]+k);
            }
        }
    }

    for (ll j = BOUND-1; j >= 0; j--) {
        for (ll k = 1; j-idx*k >= 0 && k <= take; k++) {
            knap_max[j] = max(knap_max[j], knap_max[j-idx*k]+k);
        }
    }

    ll goal = sum-L, ans = -INF;
    for (ll i = goal; i < BOUND; i++) {
        ans = max(ans, cnt-knap_min[i]+knap_max[i-goal]);
    }

    if (ans == -INF) cout << "impossible";
    else cout << ans;

    return 0;
}

/*
1 5
0 0 6
*/

• 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