Submission #464835

#	Time	Username	Problem	Language	Result	Execution time	Memory
464835		Qw3rTy	Knapsack (NOI18_knapsack)	C++11	0 / 100	0 ms	332 KiB

knapsack

#include <bits/stdc++.h>
#define int long long
#define pi pair<int,int>
#define fi first
#define se second
using namespace std;

const int maxN = 1e5+5;
const int maxV = 2e3+5;
int cnt = 0;
pi item[maxN*40]; //.fi = value; .se = weight;
int id[maxN*40];
int baseVal[maxN];
int f[maxV];
int a[maxN];
int S,N;

bool cmp(pi a, pi b){
	return a.se > b.se;
}

signed main(){
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	//freopen("../test.in","r",stdin);
	cin >> S >> N;
	for(int i = 1; i <= N; ++i){
		int v,w,k; cin >> v >> w >> k;
		a[i] = k;
		baseVal[i] = v;
		int j = 1;
		while(j <= k){
			item[++cnt] = pi(v*j,w*j);
			id[cnt] = i;
			j = j * 2;
		}
	}
	sort(item+1,item+cnt+1,cmp);
	for(int i = 1; i <= cnt; ++i){
		for(int j = S; j >= item[i].se; --j){
			if(f[j-item[i].se] + item[i].fi > f[j]){
				//There are still this many items
				int amount = item[i].fi / baseVal[id[i]];
				if(a[id[i]] >= amount){
					a[id[i]] -= amount;
					f[j] = max(f[j], f[j-item[i].se] + item[i].fi);
				}
			}
		}
	}
	cout << f[S] << '\n';
}

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