Submission #860597

#TimeUsernameProblemLanguageResultExecution timeMemory
860597E869120Uplifting Excursion (BOI22_vault)C++14
20 / 100
1759 ms47556 KiB
#include <bits/stdc++.h>
using namespace std;

vector<long long> solve(long long N, long long LIM, vector<long long> List) {
    vector<long long> dp(LIM + 1, -(1LL << 60));
    dp[0] = 0;

    // DP Start
    for (int i = 0; i < N; i++) {
        vector<long long> ndp(LIM + 1, -(1LL << 60));
        long long kazu = i + 1;
        for (int j = 0; j < kazu; j++) {
            vector<pair<long long, long long>> maxi;
            int cur = 0;
            for (int k = j; k <= LIM; k += kazu) {
                long long val = dp[k] - (k / kazu);
                while (maxi.size() >= cur + 1) {
                    if (maxi[maxi.size() - 1].second <= val) maxi.pop_back();
                    else break;
                }
                maxi.push_back(make_pair(1LL * k, val));
                if (maxi[cur].second >= -(1LL << 59)) ndp[k] = maxi[cur].second + (k / kazu);
                while (cur < (int)maxi.size() && maxi[cur].first <= k - 1LL * kazu * List[i]) cur += 1;
            }
        }
        dp = ndp;
    }

    // Return
    return dp;
}

int main() {
    // Step 1. Input
    long long M, L;
    cin >> M >> L;
    vector<long long> A(2 * M + 1, 0);
    for (int i = 0; i <= 2 * M; i++) cin >> A[i];

    // Step 2. Calculate
    vector<long long> A1;
    vector<long long> A2;
    for (int i = M - 1; i >= 0; i--) A1.push_back(A[i]);
    for (int i = M + 1; i <= 2 * M; i++) A2.push_back(A[i]);
    vector<long long> DP1 = solve(M, 700000, A1);
    vector<long long> DP2 = solve(M, 700000, A2);

    // Step 3. Output
    long long Answer = -(1LL << 60);
    for (long long i = 0; i <= 700000LL - abs(L); i++) {
        long long idx1 = i;
        long long idx2 = i + abs(L); if (L < 0) swap(idx1, idx2);
        Answer = max(Answer, DP1[idx1] + DP2[idx2]);
    }
    if (Answer < 0LL) cout << "impossible" << endl;
    else cout << Answer + A[M] << endl;
    return 0;
}

Compilation message (stderr)

vault.cpp: In function 'std::vector<long long int> solve(long long int, long long int, std::vector<long long int>)':
vault.cpp:17:36: warning: comparison of integer expressions of different signedness: 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   17 |                 while (maxi.size() >= cur + 1) {
      |                        ~~~~~~~~~~~~^~~~~~~~~~
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...