Submission #629500

#	Time	Username	Problem	Language	Result	Execution time	Memory
629500		leeminhduc2	Knapsack (NOI18_knapsack)	C++17	100 / 100	129 ms	8344 KiB

knapsack

#include <bits/stdc++.h>
#define ll int
#define ft first
#define sc second
using namespace std;
const int N=1e5+10;
ll s,n,dp[N];
vector <pair<int,int>> v[N];
vector <int>pre[N];
int cal(int i,int j)
{
    return pre[i][j-1];
}
void lulu_solution()
{
    cin >> s >> n;
    for (int i=1;i<=s;i++) dp[i]=-1044266559;
    dp[0]=0;
    int res=dp[1];
    for (ll i=1;i<=n;i++)
    {
        int val,w,k;
        cin >> val >>w >> k;
        v[w].push_back({val,k});
    }
    for (ll i=1;i<=s;i++)
    {
        sort(v[i].begin(),v[i].end(),greater<pair<ll,ll>>());
        int cur=0;
        int cnt=s/i;
        for (int j=0;j<v[i].size();j++)
        {
            while (v[i][j].sc&&cnt)
            {
                cur+=v[i][j].ft;
                --cnt;
                --v[i][j].sc;
                pre[i].push_back(cur);
            }
        }
    }
    for (ll i=1; i<=s; i++)
    {
        for (int j=s;j>=i;j--)
        {
            for (int k=j-i;(k>=0&&(j-k)/i<=(int) pre[i].size());k-=i) dp[j]=max(dp[j],dp[k]+cal(i,(j-k)/i));
        }
    }
    cout << *max_element(dp,dp+s+1);

}
signed main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    lulu_solution();
}

Compilation message (stderr)

knapsack.cpp: In function 'void lulu_solution()':
knapsack.cpp:31:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   31 |         for (int j=0;j<v[i].size();j++)
      |                      ~^~~~~~~~~~~~
knapsack.cpp:19:9: warning: unused variable 'res' [-Wunused-variable]
   19 |     int res=dp[1];
      |         ^~~

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