Submission #823517

#	Time	Username	Problem	Language	Result	Execution time	Memory
823517		uped	Knapsack (NOI18_knapsack)	C++14	100 / 100	58 ms	3876 KiB

knapsack

//
// Created by MiłoszK on 11.08.2023.
//
//  Two Sets II

#include<bits/stdc++.h>

using namespace std;

using ll = long long;

vector<ll> sieve(ll n) {
    vector<bool> is_prime(n + 1, true);
    is_prime[0] = is_prime[1] = false;
    for (ll i = 2; i <= n; i++) {
        if (is_prime[i] && (long long) i * i <= n) {
            for (ll j = i * i; j <= n; j += i)
                is_prime[j] = false;
        }
    }
    vector<ll> primes;
    for (ll i = 2; i <= n; ++i) {
        if (is_prime[i]) {
            primes.push_back(i);
        }
    }
    return primes;
}

void fastio() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
}

void fileio(const string &name) {
    freopen((name + ".in").c_str(), "r", stdin);
    freopen((name + ".out").c_str(), "w", stdout);
}


int main() {
    fastio();
    ll s, n;
    cin >> s >> n;
    map<int, vector<pair<int, int>>> items;
    vector<pair<int, int>> vp;
    for (ll i = 0; i < n; ++i) {
        int v, w, k;
        cin >> v >> w >> k;
        items[w].emplace_back(v, k);
    }
//    for (int i = 0; i <= 2000; ++i) {
//        sort(items[i].begin(), items[i].end(), greater<>());
//    }


    vector<int> dp2(s + 1);
    for (auto& [w, v] : items) {
        sort(v.begin(), v.end(), greater<>());
        for (int j = s; j >= w; --j) {
            int cnt_w = 0;
            int cnt_v = 0;
            int used = 0;
            int k = 0;
            while (k < v.size()) {
                cnt_w += w;
                cnt_v += v[k].first;
                if (j - cnt_w < 0) break;
                ++used;
                if (used == v[k].second) {
                    ++k;
                    used = 0;
                }
                dp2[j] = max(dp2[j], dp2[j - cnt_w] + cnt_v);
            }
        }
//        for (int i = 0; i <= s; ++i) {
//            cout << dp2[i] << ' ';
//        }
//        cout << '\n';
    }
    cout << dp2[s];
    return 0;
}

Compilation message (stderr)

knapsack.cpp: In function 'int main()':
knapsack.cpp:58:16: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   58 |     for (auto& [w, v] : items) {
      |                ^
knapsack.cpp:65:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   65 |             while (k < v.size()) {
      |                    ~~^~~~~~~~~~
knapsack.cpp: In function 'void fileio(const string&)':
knapsack.cpp:36:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   36 |     freopen((name + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
knapsack.cpp:37:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   37 |     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