Submission #972849

#	Time	Username	Problem	Language	Result	Execution time	Memory
972849		vjudge1	Knapsack (NOI18_knapsack)	C++17	100 / 100	50 ms	5212 KiB

knapsack

#include <bits/stdc++.h>

using namespace std;
using ll = long long;

const int MAX_W = 2024;
vector<ll>dp(MAX_W, -1e18);
vector<pair<ll, ll>>vw[MAX_W];

int main(){
    ios_base::sync_with_stdio(0); cin.tie(0);
    int S, N; cin >> S >> N;
    for(int i = 1; i <= N; i++){
        ll v, w, k; cin >> v >> w >> k;
        vw[w].emplace_back(v, k);
    }

    //each weight can only be taken S/w times
    vector<pair<ll, ll>>v;
    for(int i = 1; i <= S; i++){
        if(vw[i].empty()) continue;
        sort(vw[i].begin(), vw[i].end());

        for(int j = 0; j < S/i; j++){
            if(vw[i].empty()) break;
            v.emplace_back(vw[i].back().first, i); //{val, weight}
            vw[i].back().second--;
            if(vw[i].back().second == 0) vw[i].pop_back();
        }
    }

    dp[0] = 0;
    for(auto &[val, wt]: v){
        for(int i = S; i >= wt; i--) dp[i] = max(dp[i], dp[i - wt] + val);
    }

    ll ans = 0;
    for(int i = 1; i <= S; i++) ans = max(ans, dp[i]);
    cout << ans << '\n';
    
    return 0;
}

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