Submission #956628

#	Time	Username	Problem	Language	Result	Execution time	Memory
956628		Ariadna	Knapsack (NOI18_knapsack)	C++14	49 / 100	42 ms	756 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<int, priority_queue<int>> comp;
    for (int i = 0; i < n; ++i) {
        while (comp[w[i]].size() < s/w[i] && k[i] > 0) {
            comp[w[i]].push(-v[i]);
            --k[i];
        }
        while (k[i] > 0 && -comp[w[i]].top() < v[i]) {
            comp[w[i]].pop();
            comp[w[i]].push(-v[i]);
        }
    }

    vector<pair<int, priority_queue<int>>> products;
    for (auto& x : comp) {
        priority_queue<int> pq;
        while (!x.second.empty()) {
            pq.push(-x.second.top());
            x.second.pop();
        }
        products.pb(mp(x.first, pq));
    }
    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;
}

Compilation message (stderr)

knapsack.cpp: In function 'std::vector<std::pair<long long int, std::priority_queue<long long int> > > compression(long long int, long long int, std::vector<long long int, std::allocator<long long int> >&, std::vector<long long int, std::allocator<long long int> >&, std::vector<long long int, std::allocator<long long int> >&)':
knapsack.cpp:11:34: warning: comparison of integer expressions of different signedness: 'std::priority_queue<long long int>::size_type' {aka 'long unsigned int'} and 'long long int' [-Wsign-compare]
   11 |         while (comp[w[i]].size() < s/w[i] && k[i] > 0) {

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