Submission #1346126

#	Time	Username	Problem	Language	Result	Execution time	Memory
1346126		nguthianmangcay	Knapsack (NOI18_knapsack)	C++20	100 / 100	31 ms	4300 KiB

knapsack

#include<bits/stdc++.h>
using namespace std;
const int N=1e5+3;
const int W=2e3+3;
const int K = 1e5+3;
const long long inf=1e18+3;
#define ll long long
#define fi first
#define se second
#define VOI void
#define int long long

vector<int>cand[W];

int v[N],w[N],k[N];

int nv[K],nw[K];

bool cmp(int x,int y){
    return v[x] > v[y];
}

VOI jiangly(){

    int W,n;
    cin>>W>>n;
    for(int i=1;i<=n;i++){
        cin>>v[i]>>w[i]>>k[i];
        cand[w[i]].push_back(i);
    }
    int sum_cnt = 0;
    for(int wa=1;wa<=W;wa++){
        sort(cand[wa].begin(),cand[wa].end(),cmp);
        int max_cnt = W/wa;
        int cur_cnt = 0;
        for(int i : cand[wa]){
            while(cur_cnt < max_cnt && k[i] > 0){
                nv[++sum_cnt] = v[i];
                nw[sum_cnt] = w[i];
                cur_cnt++;
                k[i]--;
            }
        }
    }
    vector<ll>pre(W+2,0);
    vector<ll>cur(W+2,0);
    for(int i=1;i<=sum_cnt;i++){
        for(int w=0;w<=W;w++){
            cur[w] = pre[w];
            if(w >= nw[i]){
                cur[w] = max(cur[w],pre[w-nw[i]] + nv[i]);
            }
        }
        pre.swap(cur);
        cur.assign(W+2,0);
    }
    cout<<pre[W];
}
int32_t main(){
    cin.tie(0)->sync_with_stdio(0);
    if(fopen("QUANSENSEI.inp","r")){
        freopen("O(0).inp","r",stdin);
    }

//    if(fopen("input.txt","r")){
//        freopen("input.txt","r",stdin);
//        freopen("output.txt","w",stdout);
//    }
    jiangly();

//    cerr << "Time elapsed: " << 1.0 * clock() / CLOCKS_PER_SEC << " s.\n";
}

Compilation message (stderr)

knapsack.cpp: In function 'int32_t main()':
knapsack.cpp:62:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   62 |         freopen("O(0).inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

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