Submission #1090011

#	Time	Username	Problem	Language	Result	Execution time	Memory
1090011		EmmaXII	Knapsack (NOI18_knapsack)	C++17	100 / 100	471 ms	7440 KiB

knapsack

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

typedef long long ll;
using vi = vector<int>;
using vvi = vector<vector<int>>;
using vll = vector<ll>;
using vvll = vector<vector<ll>>;

#define all(x) x.begin(), x.end()
#define ckmin(a,b) a = min(a,b)
#define ckmax(a,b) a = max(a,b)


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

    int N, S;
    cin >> S >> N;

    vll V(N);
    vi W(N);
    vll K(N);

    for (int i=0;i<N;i++) cin >> V[i] >> W[i] >> K[i];

    vector<vector<pair<ll,ll>>> items_by_weight(S+1);
    for (int i=0;i<N;i++) {
        items_by_weight[W[i]].push_back({V[i], K[i]});
    }

    vector<tuple<ll, int, ll>> items;
    for (int i=1;i<=S;i++) {
        sort(all(items_by_weight[i]));
        reverse(all(items_by_weight[i]));
        for (int j=0;j < items_by_weight[i].size() && j*i<=S;j++) {
            auto [v, k] = items_by_weight[i][j];
            items.push_back({i, v, k});
        }
    }


    vll dp(S+1, 0);
    for (auto [w, v, k] : items) {
        vll ndp(S+1, 0);
        for (int j=0;j<=w && j<=S;j++) {
            priority_queue<pair<ll, int>> maxes;
            for (int jp=0;j+jp*w<=S;jp++) {
                maxes.push({dp[j + jp*w] - jp*v, jp});
                while(maxes.top().second < jp - k) maxes.pop();
                ll curmax = maxes.top().first;
                ckmax(ndp[j+jp*w], curmax + jp*v);
            }
        }

        swap(ndp, dp);
    }

    cout << dp[S] << endl;

    return 0;
}

Compilation message (stderr)

knapsack.cpp: In function 'int main()':
knapsack.cpp:37:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   37 |         for (int j=0;j < items_by_weight[i].size() && j*i<=S;j++) {
      |                      ~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

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