Submission #823514

#	Time	Username	Problem	Language	Result	Execution time	Memory
823514		uped	Knapsack (NOI18_knapsack)	C++14	0 / 100	8 ms	468 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);
}
//ll MOD = 1e9 + 7;
//ll TWO_MOD_INV = 500000004;
//struct Item {
//    int value;
//    int weight;
//    int amount;
//};


int main() {
    fastio();

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


    vector<int> dp2(s + 1);
//    for (ll i = n - 1; i >= 0; --i) {
//        for (ll j = s; j >= items[i].weight; --j) {
//            for (ll k = 0; k <= items[i].amount && j - (items[i].weight * k) >= 0; ++k) {
//                dp2[j] = max(dp2[j], dp2[j - items[i].weight * k] + items[i].value * k);
//            }
//        }
//    }

//    for (int i = s; i > 0; --i) {
//        for (int j = s; j >= i; --j) {
//            int cnt_w = 0;
//            int cnt_v = 0;
//            int k = 0;
//            while (j - cnt_w >= 0 && k < items[i].size()) {
//                cnt_w += i;
//                cnt_v += items[i][k].first;
//                --(items[i][k].second);
//                if (items[i][k].second == 0) {
//                    ++k;
//                }
//                dp2[i][j] = max(dp2[i][j], dp2[i + 1][cb] + cnt_v);
//                //dp2[j] = max(dp2[j], dp2[j - cnt_w] + cnt_v);
//            }
//        }
//    }

    for (int i = s; i > 0; --i) {
        for (int j = s; j >= i; --j) {
            int cnt_w = 0;
            int cnt_v = 0;
            int used = 0;
            int k = 0;
            while (j - cnt_w >= 0 && k < items[i].size()) {
                cnt_w += i;
                cnt_v += items[i][k].first;
                ++used;
                if (used == items[i][k].second) {
                    ++k;
                    used = 0;
                }
                //dp2[i][j] = max(dp2[i][j], dp2[i + 1][cb] + cnt_v);
                dp2[j] = max(dp2[j], dp2[j - cnt_w] + cnt_v);
            }
        }
    }
    cout << dp2[s];
//    vector<ll> dp2(s + 1);
//    for (ll i = vp.size() - 1; i >= 0; --i) {
//        for (ll j = s; j >= vp[i].second; --j) {
//            dp2[j] = max(dp2[j], dp2[j - vp[i].second] + vp[i].first);
//        }
//    }
    //cout << dp2[s];
    return 0;
}

Compilation message (stderr)

knapsack.cpp: In function 'int main()':
knapsack.cpp:100:40: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  100 |             while (j - cnt_w >= 0 && k < items[i].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: 0 / 12
• Subtask 2: 0 / 17
• Subtask 3: 0 / 20
• Subtask 4: 0 / 24
• Subtask 5: 0 / 27