Submission #791140

#	Time	Username	Problem	Language	Result	Execution time	Memory
791140		BBart888	Knapsack (NOI18_knapsack)	C++14	100 / 100	63 ms	5356 KiB

knapsack

#include <iostream>
#include <vector>
#include <map>
#include <set>
#include<algorithm>
#include <string>
#include <cmath>
#include <cstring>
#include <queue>
#include<iomanip>
#include <array>




using namespace std;



const int MAXN = 1e6+ 11;
const int MOD = 1e9+7;
using ll = long long;
using ld = long double;
const int K = 26;


ll n,S;
ll v[MAXN];
ll weight[MAXN];
ll k[MAXN];

vector<pair<ll, int>> obj[4000];











int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);




    //freopen("cowjog.in", "r", stdin);

    //freopen("cowjog.out", "w", stdout);

    
    
    cin >> S >> n;


    for (int i = 0; i < n; i++)
        cin >> v[i] >> weight[i] >> k[i];

    ll mx = *max_element(k, k + n);

    if (n == 1)
        cout << v[0] * min(k[0],S/weight[0]) << '\n';
    else if (n <= 100 && mx <= 10)
    {
        ll dp[2300];
        memset(dp, 0, sizeof dp);
        
        for (int i = 0; i < n; i++)
        {
            for (int j = 1; j <= k[i]; j++)
            {
                for (int w = S; w >= 0; w--)
                {
                    if ((w == 0 || dp[w] > 0) && w + weight[i] <= S)
                    {
                        dp[w + weight[i]] = max(dp[w + weight[i]], dp[w] + v[i]);
                    }
                }
            }
        }


        ll ans = 0;
        for (int i = 1; i <= S; i++)
            ans = max(ans, dp[i]);


        cout << ans << '\n';


    }
    else
    {
        ll dp[2300];
        memset(dp, 0, sizeof dp);

        for (int i = 0; i < n; i++)
            obj[weight[i]].push_back({ v[i],k[i] });


        for (int i = 1; i <= S; i++)
        {
            if (obj[i].size() == 0)
                continue;
            sort(obj[i].begin(), obj[i].end(),greater<pair<ll,ll>>());
            int id = 0;
            for (int j = 1; j*i <= S; j++)
            {
                if (id >= obj[i].size())
                    break;

                for (int w = S; w >= 0; w--)
                {
                    if ((w == 0 || dp[w] > 0) && w + i <= S)
                    {
                        dp[w + i] = max(dp[w + i], dp[w] + obj[i][id].first);
                    }
                }
                obj[i][id].second--;
                if (obj[i][id].second == 0)
                    id++;
            }
        }


        ll ans = 0;

        for (int i = 1; i <= S; i++)
            ans = max(ans, dp[i]);

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









    return 0;
}

Compilation message (stderr)

knapsack.cpp: In function 'int main()':
knapsack.cpp:115:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  115 |                 if (id >= obj[i].size())
      |                     ~~~^~~~~~~~~~~~~~~~

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