Submission #956413

#	Time	Username	Problem	Language	Result	Execution time	Memory
956413		Ariadna	Knapsack (NOI18_knapsack)	C++14	12 / 100	1 ms	348 KiB

knapsack

#include <bits/stdc++.h>
#define pb push_back
#define mp make_pair
#define int long long

using namespace std;

vector<pair<int, priority_queue<int>>> compression(int n, int s, vector<int>& v, vector<int>& w, vector<int>& k) {
    map<pair<int, int>, int> comp;
    for (int i = 0; i < n; ++i) {
        comp[{v[i], w[i]}] += k[i];
    }
 
    for (auto& x : comp) {
        if (x.second >= 3) {
            comp[{2 * x.first.first, 2*x.first.second}] += (x.second - 1) / 2;
            if (x.second % 2) comp[x.first] = 1;
            else comp[x.first] = 2;
        }
    }

    map<int, priority_queue<int>> comp2;
    for (auto& x : comp) {
        if (x.first.second * ((int)comp2[x.first.second].size()+1) > s) continue;
        comp2[x.first.second].push(x.first.first);
        if (x.second == 2)
            comp2[x.first.second].push(x.first.first);
    }

    vector<pair<int, priority_queue<int>>> products;
    for (auto& x : comp2) {
        products.pb(mp(x.first, x.second));
    }

    return products;
} 

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(NULL);

    int s, n;
    cin >> s >> n;
    vector<int> v(n), w(n), k(n);
    for (int i = 0; i < n; ++i) {
        cin >> v[i] >> w[i] >> k[i];
    }

    vector<pair<int, priority_queue<int>>> products = compression(n, s, v, w, k);
    int N = (int)products.size();

    vector<int> prev_dp(s+1, 0), curr_dp(s+1, 0);
    for (int i = 0; i < N; ++i) {
        curr_dp = vector<int>(s+1, 0);
        for (int j = 1; j <= s; ++j) {
            curr_dp[j] = prev_dp[j];
            int cnt = 1, value = 0;
            priority_queue<int> pq = products[i].second;
            while (cnt*products[i].first <= j && !pq.empty()) {
                value += pq.top();
                pq.pop();
                curr_dp[j] = max(curr_dp[j], prev_dp[j-cnt*products[i].first] + value);
                ++cnt;
            }
        }
        prev_dp = curr_dp;
    }
    cout << curr_dp[s] << '\n';

    return 0;
}

• Subtask 1: 12 / 12
• Subtask 2: 0 / 17
• Subtask 3: 0 / 20
• Subtask 4: 0 / 24
• Subtask 5: 0 / 27