Submission #1162803

#	Time	Username	Problem	Language	Result	Execution time	Memory
1162803		uakkes	Knapsack (NOI18_knapsack)	C++20	100 / 100	40 ms	4168 KiB

knapsack

//
// All truth are easy to understand once they are discovered.
// The point is to discover them
//
#include <bits/stdc++.h>
using namespace std;

const int N = 2e5 + 123;

void solve(){
    int n, S; cin >> S >> n;
    int v[n], w[n], k[n];
    vector<pair<long long, int>> weights[S+1];
    for (int i = 0; i < n; i++) {
        cin >> v[i] >> w[i] >> k[i];
        weights[w[i]].push_back({v[i], k[i]});
    }

    for (int i = 1; i < S+1; i++) {
        sort(weights[i].begin(), weights[i].end(), greater());
        weights[i].resize(min((int)weights[i].size(), S / i));
    }

    long long dp[S+1];
    memset(dp, -1, sizeof(dp));
    dp[0] = 0;

    for (int i = 1; i <= S; i++) {
        int cnt = 0;
        for (auto [val, times] : weights[i]) {
            for (int j = 0; j < times; j++) {
                if (cnt == S / i) break;
                for (int x = S; x >= i; x--) {
                    if (dp[x - i] != -1) dp[x] = max(dp[x - i] + val, dp[x]);
                }
                cnt++;
            }
            if (cnt == S / i) break;
        }
    }

    long long ans = 0;
    for (int i = 0; i <= S; i++) {
        ans = max(ans, dp[i]);
    }
    cout << ans;
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    int tt = 1;
//     cin >> tt;

    while (tt--) {
        solve();
        cout << '\n';
    }

    return 0;
}

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