Submission #652329

#	Time	Username	Problem	Language	Result	Execution time	Memory
652329		lam	Knapsack (NOI18_knapsack)	C++14	100 / 100	116 ms	62256 KiB

knapsack

#include <bits/stdc++.h>
#define int long long
using namespace std;
const int maxn = 1e6 + 10;
typedef pair<int,int> ii;
#define ff first
#define ss second
int s,n;
int v[maxn],w[maxn],k[maxn];
vector <ii> a[maxn];
int dp[2010][2010];
signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr); cout.tie(nullptr);
    cin>>s>>n;
    for (int i=1; i<=n; i++)
    {
        cin>>v[i]>>w[i]>>k[i];
        a[w[i]].push_back({v[i],k[i]});
    }
    for (int i=1; i<=s; i++)
    {
        sort(a[i].begin(),a[i].end(),greater<ii>());
        for (int j=1; j<=s; j++)
        {
            dp[i][j]=dp[i-1][j];
            if (a[i].empty()) continue;
            int it,cnt,used,val;
            it=cnt=val=0;
            used=a[i][it].ss;
            while (it<(int)(a[i].size()) && (cnt+1)*i <=j )
            {
                used--;
                cnt++;
                val+=a[i][it].ff;
                dp[i][j]=max(dp[i][j],dp[i-1][j-cnt*i]+val);
                if (used==0)
                {
                    it++;
                    if (it<a[i].size()) used=a[i][it].ss;
                }
            }
        }
    }
    int ans=0;
    for (int i=1; i<=s; i++) ans=max(ans,dp[s][i]); cout<<ans;
}

Compilation message (stderr)

knapsack.cpp: In function 'int main()':
knapsack.cpp:41:27: 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]
   41 |                     if (it<a[i].size()) used=a[i][it].ss;
      |                         ~~^~~~~~~~~~~~
knapsack.cpp:47:5: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
   47 |     for (int i=1; i<=s; i++) ans=max(ans,dp[s][i]); cout<<ans;
      |     ^~~
knapsack.cpp:47:53: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
   47 |     for (int i=1; i<=s; i++) ans=max(ans,dp[s][i]); cout<<ans;
      |                                                     ^~~~

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