Submission #917510

#	Time	Username	Problem	Language	Result	Execution time	Memory
917510		PieArmy	Knapsack (NOI18_knapsack)	C++17	100 / 100	73 ms	19536 KiB

knapsack

#include <bits/stdc++.h>
#define fr first
#define sc second
#define pb push_back
#define endl '\n';
typedef long long ll;
const ll inf=2000000000000000005;
using namespace std;
ll pie(ll army){return (1ll<<army);}
ll fpow(ll x,ll y,ll m=0){if(y<0){cout<<"powError";return -1;}if(m)x%=m;ll res=1;while(y>0){if(y&1)res*=x;x*=x;if(m){x%=m;res%=m;}y>>=1;}return res;}

void code(){
    int k,n;cin>>k>>n;
    map<int,vector<pair<int,int>>>mp;
    vector<int>w;
    for(int i=0;i<n;i++){
        int x,y,z;cin>>x>>y>>z;
        mp[y].pb({x,z});
        if(mp[y].size()==1)w.pb(y);
    }
    int m=w.size();
    vector<vector<int>>dp(m+1,vector<int>(k+1,0));
    for(int i=0;i<m;i++){
        vector<pair<int,int>>&v=mp[w[i]];
        int s=v.size();
        sort(v.begin(),v.end(),[&](const pair<int,int> &x,const pair<int,int> &y){return x.fr>y.fr;});
        for(int j=0;j<=k;j++){
            dp[i+1][j]=max(dp[i+1][j],dp[i][j]);
            int carp=0,sum=0;
            for(int pos=0;pos<s;pos++){
                int cur=v[pos].sc;
                while(cur--){
                    carp++;
                    if(carp*w[i]+j>k)break;
                    sum+=v[pos].fr;
                    dp[i+1][carp*w[i]+j]=max(dp[i+1][carp*w[i]+j],dp[i][j]+sum);
                }
                if(carp*w[i]+j>k)break;
            }
        }
    }
    int ans=0;
    for(int x:dp[m])ans=max(ans,x);
    cout<<ans;
}

int main(){
    ios_base::sync_with_stdio(false);cin.tie(NULL);
    bool usaco=0;if(usaco){freopen(".in","r",stdin);freopen(".out","w",stdout);}
    int t=1;
    if(!t)cin>>t;
    while(t--){code();cout<<endl;}
    return 0;
}

Compilation message (stderr)

knapsack.cpp: In function 'int main()':
knapsack.cpp:49:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   49 |     bool usaco=0;if(usaco){freopen(".in","r",stdin);freopen(".out","w",stdout);}
      |                            ~~~~~~~^~~~~~~~~~~~~~~~~
knapsack.cpp:49:60: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   49 |     bool usaco=0;if(usaco){freopen(".in","r",stdin);freopen(".out","w",stdout);}
      |                                                     ~~~~~~~^~~~~~~~~~~~~~~~~~~

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