Submission #1357774

#	Time	Username	Problem	Language	Result	Execution time	Memory
1357774		kai	Knapsack (NOI18_knapsack)	C++20	100 / 100	26 ms	3188 KiB

knapsack

#include <bits/stdc++.h>

using namespace std;

#define int long long
#define el '\n'
#define all(x) begin(x), end(x)
#define sz(s) (int)(s.size())

inline void setIO(string s) {
    if(fopen((s + ".in").c_str(), "r")){
        freopen((s + ".in").c_str(), "r", stdin);
        freopen((s + ".out").c_str(), "w", stdout);
    }
}

const int MOD = 1e9+7; //998244353;
const int N = 1e6 + 36;
const int MAX_S = 2000 + 18;
int f[MAX_S];
vector<pair<int, int>> vt[MAX_S];
int n, v, w, k, s;

void Solve(){
    cin>> s>> n;
    for(int i=0; i<n; i++){
        cin>> v>> w>> k;
        vt[w].push_back({v, k});
    }

    vector<pair<int, int>> process;
    for(int w = 1; w<=s; w++){
        sort(all(vt[w]), greater<pair<int, int>>());

        int need = s/w;
        for(auto &[v, k]: vt[w]){
            int lim = min(k, need);
            for(int t=0; t<lim; t++){
                process.push_back({v, w});
            }
            need -= lim;
            if(need == 0) break;
        }
    }

    for(auto &[v, w]: process){
        for(int j = s; j>=w; j--){
            f[j] = max(f[j], f[j-w] + v);
        }
    }

    cout<< *max_element(f+1, f+s+1);
}

signed main (){
    setIO("Rem");
    ios_base::sync_with_stdio(false);
    cin.tie(0), cout.tie(0);

    int T(1);
    // cin >> T;
    while(T--) Solve();

    return 0;
}

Compilation message (stderr)

knapsack.cpp: In function 'void setIO(std::string)':
knapsack.cpp:12:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   12 |         freopen((s + ".in").c_str(), "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
knapsack.cpp:13:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   13 |         freopen((s + ".out").c_str(), "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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