Submission #1312660

#	Time	Username	Problem	Language	Result	Execution time	Memory
1312660		coderg	Knapsack (NOI18_knapsack)	C++20	100 / 100	27 ms	1780 KiB

knapsack

#include "bits/stdc++.h"
using namespace std;
#define mp make_pair
#define fi first
#define se second
#define pii pair<int,int>
#define yes cout<<"YES\n"
#define no cout<<"NO\n"
#define pb push_back
void setIO(string name = ""){if(name.size()){ freopen((name + ".in").c_str(), "r", stdin);freopen((name + ".out").c_str(), "w", stdout);}}
#define F(i,l,r) for(int i=(l);i<(r);++i)
#define FR(i,l,r) for(int i=(l);i>=(r);--i)
typedef long long ll;

const int maxn=2005;
const int mod=1e9+7;
const int mox=2000*500+505;
const int inf=1e9;

ll dp[maxn];

void solve(){
int s,n;
cin>>s>>n;
vector<pii> items[maxn];
F(i,0,n){
    int v,w,k;
    cin>>v>>w>>k;
    if(w<=s)items[w].pb({v,k});
}
memset(dp,-1,sizeof dp);
dp[0]=0;
F(w,1,s+1){
    if(items[w].empty())continue;
    sort(items[w].rbegin(),items[w].rend());
    int lim=s/w,taken=0;
    for(auto& y:items[w]){
        if(taken>=lim)break;
        int take=min(y.se,lim-taken),x=take,p=1;
        while(x){
            int cur=min(x,p),wei=cur*w;
            ll val=(ll)cur*y.fi;
            FR(j,s,wei){
                if(dp[j-wei]!=-1)dp[j]=max(dp[j],dp[j-wei]+val);
            }
            x-=cur;
            p<<=1;
        }
        taken+=take;
    }
}
ll ans=0;
F(i,0,s+1){
    if(dp[i]!=-1)ans=max(ans,dp[i]);
}
cout<<ans<<'\n';
}

signed main() {
    ios_base::sync_with_stdio(0);cin.tie(nullptr);
   // setIO("bank");

    int tt=1;
   // cin>>tt;
    while(tt--)solve(); 

    return 0;
}

Compilation message (stderr)

knapsack.cpp: In function 'void setIO(std::string)':
knapsack.cpp:10:54: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   10 | void setIO(string name = ""){if(name.size()){ freopen((name + ".in").c_str(), "r", stdin);freopen((name + ".out").c_str(), "w", stdout);}}
      |                                               ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
knapsack.cpp:10:98: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   10 | void setIO(string name = ""){if(name.size()){ freopen((name + ".in").c_str(), "r", stdin);freopen((name + ".out").c_str(), "w", stdout);}}
      |                                                                                           ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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