Submission #1272596

#	Time	Username	Problem	Language	Result	Execution time	Memory
1272596		nthvn	Knapsack (NOI18_knapsack)	C++20	29 / 100	2 ms	580 KiB

knapsack

#include "bits/stdc++.h"
using namespace std;
#define int long long

#define fi first
#define se second
#define pii pair<int,int> 
#define all(x) x.begin(), x.end()
#define sz(x) (int)x.size()
#define pb push_back
#define ll long long
const int S= 2005, N=1e5+5;
int s,n;
struct DATA{
	int v,w,k;
	bool operator <(const DATA &o) const{
		return v*o.w< w*o.v;
	}
	void print(){
		cerr<<v<<" "<<w<<" "<<k<<"\n";
	}
} a[N];

int dp[2][S];

signed main(){
	ios_base::sync_with_stdio(NULL);
	cin.tie(NULL);
	if(fopen("TASK.INP", "r")){
		freopen("TASK.INP", "r", stdin);
		freopen("TASK.OUT", "w", stdout);
	}
	cin>>s>>n;
	for(int i=1;i<=n;i++){
		int v,w,k; cin>>v>>w>>k;
		a[i] = {v,w,k};
	}
	sort(a+1,a+n+1);
	// for(int i=1;i<=n;i++) a[i].print();
	
	for(int i=1;i<=n;i++){
		int v= a[i].v, w= a[i].w, k= a[i].k;
		for(int j=0;j<=s;j++){
			int cnt = min(k, j/w);
			dp[i&1][j] = max(dp[(i-1)&1][j], dp[(i-1)&1][j-cnt*w]+cnt*v);
			// cerr<<i<<" "<<j<<" "<<dp[i&1][j]<<"\n";
		}
		
	}
	cout<<*max_element(&dp[n&1][0], &dp[n&1][s+1]);
	
}

Compilation message (stderr)

knapsack.cpp: In function 'int main()':
knapsack.cpp:30:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   30 |                 freopen("TASK.INP", "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
knapsack.cpp:31:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   31 |                 freopen("TASK.OUT", "w", stdout);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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