Submission #834551

#	Time	Username	Problem	Language	Result	Execution time	Memory
834551		VMaksimoski008	Knapsack (NOI18_knapsack)	C++14	100 / 100	80 ms	36412 KiB

knapsack

#include <bits/stdc++.h>

#define pb push_back
#define eb emplace_back
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define uniq(x) x.erase(unique(all(x)), x.end())
#define rall(x) x.rbegin(), x.rend()
//#define int long long

using namespace std;

using ll = long long;
using ull = unsigned long long;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;

const int mod = 1e9 + 7;
const int LOG = 20;
const int maxn = 1e5 + 5;
const double eps = 1e-9;

void setIO() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
}

struct Item { int v, w, k; };

int32_t main() {
    setIO();

    int s, n;
    cin >> s >> n;

    vector<Item> v(n);
    map<int, vector<pii> > mp;

    for(Item &it : v) {
        cin >> it.v >> it.w >> it.k;
        mp[it.w].push_back({ it.v, it.k });
    }

    // for(auto &x : mp) {
    //     cout << x.first << '\n';
    //     for(auto &el : x.second) {
    //         cout << "{ " << el.first << ", " << el.second << " } \n";
    //     }
    // }

    vector<vector<ll> > dp(mp.size()+1, vector<ll>(s+1, -1));
    dp[0][0] = 0;

    int id = 1;
    for(auto &currVec : mp) {
        int currW = currVec.first;
        vector<pii> items = currVec.second;
        sort(all(items));
        reverse(all(items));

        for(int j=0; j<=s; j++) {
            dp[id][j] = dp[id-1][j];

            int currProd = 0;
            int totalProducts = 0;
            ll gain = 0;
            int currBuy = 0;

            while(currProd < sz(items) && (currBuy + 1) * currW <= j) {
                gain += items[currProd].first;
                totalProducts++;
                currBuy++;

                if(j >= currBuy * currW && dp[id-1][j-currBuy*currW] != -1) {
                    dp[id][j] = max(
                        dp[id][j],
                        dp[id-1][j-currBuy*currW] + gain
                    );
                }

                if(totalProducts == items[currProd].second) {
                    currProd++;
                    totalProducts = 0;
                }
            }
        }

        id++;
    }

    ll ans = 0;
    int bestW = -1;
    for(int i=0; i<=s; i++) {
        if(dp[mp.size()][i] > ans) {
            ans = dp[mp.size()][i];
            bestW = i;
        }
    }

    // for(int id=1; id<=mp.size(); id++) {
    //     for(int j=1; j<=s; j++) {
    //         cout << dp[id][j] << " ";
    //         if(j == s) cout << '\n';
    //     }
    // }

    cout << ans << '\n';
    return 0;
}

Compilation message (stderr)

knapsack.cpp: In function 'int32_t main()':
knapsack.cpp:94:9: warning: variable 'bestW' set but not used [-Wunused-but-set-variable]
   94 |     int bestW = -1;
      |         ^~~~~

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