Submission #906424

#	Time	Username	Problem	Language	Result	Execution time	Memory
906424		SalihSahin	Knapsack (NOI18_knapsack)	C++17	73 / 100	200 ms	262144 KiB

knapsack

#include<bits/stdc++.h>
#define int long long
#define pb push_back
#define mp make_pair
using namespace std;
 
const int mod = 1e9 + 7;
const int inf = 1e17*2;
const int N = 2e5 + 5;
 
int32_t main(){
    cin.tie(0); cout.tie(0);
    ios_base::sync_with_stdio(false);
    int s, n;
    cin>>s>>n;
    vector<int> items[s+1];
    for(int i = 0; i < n; i++){
        int v, w, k;
        cin>>v>>w>>k;
        for(int j = 1; j <= min(k, s/w); j++){
            items[w].pb(v);
        }
        /*
        vector<int> cnt(11);
        cnt[0] = min(k, 2048LL);
        for(int i = 0; i < 10; i++){
            int x = (cnt[i] - 1)/2;
            cnt[i] -= x*2;
            cnt[i+1] += x;
        }

        for(int i = 0; i < 10; i++){
            if((1 << i) * w > s) break;

            for(int j = 0; j < cnt[i]; j++){
                items[w * (1 << i)].pb(v * (1 << i));
            }
        }
        */
    }
 
    vector<pair<int, int> > arr;
    for(int i = 1; i <= s; i++){
        sort(items[i].rbegin(), items[i].rend());
        while(items[i].size() * i > s){
            items[i].pop_back();
        }
        for(auto it: items[i]) arr.pb(mp(i, it));
    }
 
    vector<int> dp(s+1);
    for(int i = 0; i < arr.size(); i++){
        for(int j = s - arr[i].first; j >= 0; j--){
            dp[j + arr[i].first] = max(dp[j + arr[i].first], dp[j] + arr[i].second);
        }
    }  
    int ans = 0;
    for(int i = 0; i <= s; i++){
        ans = max(ans, dp[i]);
    }
 
    cout<<ans<<endl;
    return 0;
}

Compilation message (stderr)

knapsack.cpp: In function 'int32_t main()':
knapsack.cpp:45:35: warning: comparison of integer expressions of different signedness: 'long long unsigned int' and 'long long int' [-Wsign-compare]
   45 |         while(items[i].size() * i > s){
      |               ~~~~~~~~~~~~~~~~~~~~^~~
knapsack.cpp:52:22: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   52 |     for(int i = 0; i < arr.size(); i++){
      |                    ~~^~~~~~~~~~~~

• Subtask 1: 12 / 12
• Subtask 2: 17 / 17
• Subtask 3: 20 / 20
• Subtask 4: 24 / 24
• Subtask 5: 0 / 27