Submission #820176

#	Time	Username	Problem	Language	Result	Execution time	Memory
820176		uped	Knapsack (NOI18_knapsack)	C++14	73 / 100	1079 ms	2768 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();
    vector<Item> items;
    ll s, n;

    cin >> s >> n;
    items.resize(n);
    for (ll i = 0; i < n; ++i) {
        int v, w, k;
        cin >> v >> w >> k;
        items[i] = {v, w, k};
    }
//    vector<vector<ll>> dp(s + 1, vector<ll>(n + 1));
//
//    for (ll i = n - 1; i >= 0; --i) {
//        for (ll j = 0; j <= s; ++j) {
//            for (ll k = 0; k <= items[i].amount; ++k) {
//                if (j - items[i].weight * k >= 0) {
//                    dp[j][i] = max(dp[j][i], dp[j - items[i].weight * k][i + 1] + items[i].value * k);
//                } else {
//                    break;
//                }
//            }
//        }
//    }
    vector<ll> dp2(s + 1);
    for (ll i = n - 1; i >= 0; --i) {
        for (ll j = s; j >= 0; --j) {
            for (ll k = 0; k <= items[i].amount; ++k) {
                if (j - (items[i].weight * k) >= 0) {
                    dp2[j] = max(dp2[j], dp2[j - items[i].weight * k] + items[i].value * k);
                } else {
                    break;
                }
//                cout << "item: " << i << " capacity: " << j << " amount: " << k << '\n';
//                for (int l = 0; l < s + 1; ++l) {
//                    cout << dp2[l] << ' ';
//                }
//                cout << '\n';
            }
        }
    }
    cout << dp2[s];
    return 0;
}

Compilation message (stderr)

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: 0 / 27