Submission #1306637

#	Time	Username	Problem	Language	Result	Execution time	Memory
1306637		maximusaurelius	Knapsack (NOI18_knapsack)	C++20	100 / 100	117 ms	128352 KiB

knapsack

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

using ll = long long;
using vi = vector<int>;
using ii = pair<int, int>;
using str = string;

#define pb push_back
#define mp make_pair
#define all(x) begin(x), end(x)
#define sz(x) (int) (x).size()
#define f first
#define s second
#define endl "\n"

constexpr ll MOD = 1000000007;

void setIO(string name = "") {
    ios::sync_with_stdio(0); cin.tie(0);
    if (sz(name)) {
        freopen((name + ".in").c_str(), "r", stdin);
        freopen((name + ".out").c_str(), "w", stdout);
    }
}

int main() {
    setIO();
    int S; cin >> S;
    int n; cin >> n;
    vector<vi> a_or(n);
    vector<vi> a1;
    for (int i = 0; i < n; i++)
    {
        int v, w, k; cin >> v >> w >> k;
        a_or[i] = {w,-v,k};
    }
    sort(all(a_or));
    a_or.pb({100000000,0,0});
    int cur_w = a_or[0][0];
    int cur_added = 0;
    // evtl doppelte? schlechter?

    for (int i = 0; i < n; i++)
    {
        if (a_or[i][0] > cur_w) {
            cur_w=a_or[i][0];
            cur_added=0;
        } 
        if (cur_w == 100000000) break;
        if (cur_added+a_or[i][2] <= S / cur_w) {
            a1.pb({a_or[i][0],a_or[i][1],a_or[i][2]});
            cur_added+=a_or[i][2];
        } else if (S / cur_w - cur_added > 0){
            a1.pb({a_or[i][0],a_or[i][1],S / cur_w - cur_added});
            cur_added+=S / cur_w - cur_added;
        }
    }
    
    vector<ii> test1;
    for (const auto& aa: a1) {
        for (int i = 0; i < aa[2]; i++)
        {
            test1.pb(mp(aa[0],-aa[1]));
        }
    }



    //dp
    vector<vi> dp(sz(test1)+1, vi(S+1,0));
    
    for (int i = 0; i < sz(test1); i++)
    {
        for (int j = S; j >= 0; j--)
        {
            dp[i+1][j] = dp[i][j];
            if (j - test1[i].f >= 0)dp[i+1][j]  = max(dp[i+1][j],dp[i][j-test1[i].f]+test1[i].s);
        }
    }
    
    cout << dp[sz(test1)][S] << endl;
    return 0;
}

Compilation message (stderr)

knapsack.cpp: In function 'void setIO(std::string)':
knapsack.cpp:22:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   22 |         freopen((name + ".in").c_str(), "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
knapsack.cpp:23:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   23 |         freopen((name + ".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