Submission #1081019

#	Time	Username	Problem	Language	Result	Execution time	Memory
1081019		O_Elmasry	Knapsack (NOI18_knapsack)	C++17	100 / 100	37 ms	20572 KiB

knapsack

#include <bits/stdc++.h>
#pragma GCC optimize("O3,unroll-loops")
using namespace std;
#ifdef LOCAL
#include "debug.h"
#else
#define dbg(...)
#define Timer int
#endif
#define endl '\n'
const long long mod = 1e9 + 7, Mxn = 500'005, INF = 1e18;
void solve()
{
  long long n, s;
  cin >> s >> n;
  vector<array<int, 3>>v(n + 1);
  vector<vector<array<int, 2>>>by_weight(s + 1);
  for(int i = 1;i <= n;i++){
    cin >> v[i][0] >> v[i][1] >> v[i][2];
    by_weight[v[i][1]].push_back({v[i][0], v[i][2]});
  }
  for(auto &i : by_weight)sort(i.begin(), i.end(), [](array<int, 2>a, array<int, 2>b){
    if(a[0] != b[0])return a[0] < b[0];
    return a[1] < b[1];
  });
  vector<vector<int>>dp(s + 1, vector<int>(s + 1, -100));
  dp[0][0] = 0;
  for(int i = 1;i <= s;i++){
    int sum = 0, vals = 0, cost = 0;
    dp[i] = dp[i - 1];
    for(;cost <= s && !by_weight[i].empty();){
      sum += by_weight[i].back()[0];
      cost += i;
      by_weight[i].back()[1]--;
      if(by_weight[i].back()[1] == 0)by_weight[i].pop_back();
      for(int j = cost;j <= s;j++){
        dp[i][j] = max(dp[i][j], dp[i - 1][j - cost] + sum);
      }
    }
  }
  int ans = *max_element(dp[s].begin(), dp[s].end());
  cout << ans << endl;
}
signed main()
{
  Timer timer;
  ios::sync_with_stdio(0);
  cin.tie(nullptr);
  cout.tie(nullptr);
#ifdef LOCAL
  FileRedirect("test");
#endif
  int tc = 1;
  // cin >> tc;
  for (int i = 1; i <= tc; i++)
  {
    solve();
  }
}

Compilation message (stderr)

knapsack.cpp: In function 'void solve()':
knapsack.cpp:29:18: warning: unused variable 'vals' [-Wunused-variable]
   29 |     int sum = 0, vals = 0, cost = 0;
      |                  ^~~~
knapsack.cpp: In function 'int main()':
knapsack.cpp:46:9: warning: unused variable 'timer' [-Wunused-variable]
   46 |   Timer timer;
      |         ^~~~~

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