Submission #528518

#	Time	Username	Problem	Language	Result	Execution time	Memory
528518		theysoldtheworld	Knapsack (NOI18_knapsack)	C++14	100 / 100	122 ms	6604 KiB

knapsack

#include <bits/stdc++.h>
 
using namespace std;

struct Item {
  long long v , w , k;
};
 
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int S , N;
  cin >> S >> N;
  vector<Item> a(N);
  vector<vector<pair<long long , long long>>> now(S + 1);
  for (int i = 0 ; i < N ; i++) {
    cin >> a[i].v >> a[i].w >> a[i].k;
    a[i].k = min(a[i].k , S * 1LL);
    now[a[i].w].emplace_back(a[i].v , a[i].k);
  }

  vector<Item> b;
  for (int i = 1 ; i <= S ; i++) {
    sort(now[i].rbegin(), now[i].rend());
    long long h = S;
    for (int j = 0 ; j < (int)now[i].size() ; j++) {
      long long can = min(h / i , now[i][j].second);
      if (can == 0) break;
      b.push_back({now[i][j].first , i , can});
      h -= can * i;
    }
  }

  int n = (int)b.size();
  
  vector<pair<long long , long long>> who;
  for (int i = 0 ; i < n ; i++) {
    for (int j = 0 ; j < b[i].k ; j++) {
      who.emplace_back(b[i].v , b[i].w);
    }
  }
  vector<long long> dp(S + 1);
  vector<bool> Reachable(S + 1);
  Reachable[0] = true;
  for (int i = 0 ; i < (int)who.size() ; i++) {
    for (int j = S - who[i].second ; j >= 0 ; j--) {
      if (j + who[i].second <= S && Reachable[j]) {
        Reachable[who[i].second + j] = true;
        dp[who[i].second + j] = max(dp[who[i].second + j] , dp[j] + who[i].first);
      }
    }
  }
  cout << *max_element(dp.begin(),dp.end()) << '\n';
  return 0; 
}

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