Submission #480223

#	Time	Username	Problem	Language	Result	Execution time	Memory
480223		keertan	Knapsack (NOI18_knapsack)	C++17	12 / 100	1 ms	332 KiB

knapsack

/**
 * If you live in imaginary world when your imaginary situation encounter in 
 * real situation you can't enjoiy it because you have to do pending work.
 * {This pending work appeared because you wasted that time for your useless
 * imagianry thinking.}
 */
#include<bits/stdc++.h>
using namespace std;
#define int  int64_t
#define all(x) x.begin(),x.end()
#define all1(x) x.rbegin(),x.rend()
#define sz(x) x.size()
const int N=5e5+5;
int dp[2][2001];
 priority_queue<int> q[2001];
void solve(){
    int s,n;
    cin>>s>>n;
   
    for (int i=0,x,y,z;i<n;i++){
        cin>>y>>x>>z;
        int req=s/x;
        for (int j=1;j<=min(req,z);j++){
            q[x].push(y);
            if (sz(q[x])>req){q[x].pop();}
        }
    }
    int u(0);
    int cur=1,prv=0;
    for (int i=1;i<=s;i++){
        while(!q[i].empty()){
            u=q[i].top();
            q[i].pop();
            for (int j=1;j<=s;j++){
                dp[cur][j]=dp[prv][j];
                if (j>=i && dp[cur][j]<dp[prv][j-i]+u){
                    dp[cur][j]=dp[prv][j-i]+u;
                }
            }
            swap(cur,prv);
        }
    }
    int ans=0;
    for (int i=1;i<=s;i++){ans=max(ans,dp[prv][i]);}
    cout<<ans;
}
int32_t main(){
    ios::sync_with_stdio(false);cin.tie(nullptr);cout.tie(nullptr);
    //freopen("feast.in","r",stdin);
	//freopen("feast.out","w",stdout);
    int tq=1;
    //cin>>tq;
    for (;tq;tq--){solve();}
}
//is a bruteforce possible?
//think greedier, make more assumptions
// if we you find solution using loop to decrease complexity use bs
//stuck for more than 5 minutes? move on 

Compilation message (stderr)

knapsack.cpp: In function 'void solve()':
knapsack.cpp:25:25: warning: comparison of integer expressions of different signedness: 'std::priority_queue<long int>::size_type' {aka 'long unsigned int'} and 'int64_t' {aka 'long int'} [-Wsign-compare]
   25 |             if (sz(q[x])>req){q[x].pop();}
      |                         ^

• Subtask 1: 12 / 12
• Subtask 2: 0 / 17
• Subtask 3: 0 / 20
• Subtask 4: 0 / 24
• Subtask 5: 0 / 27