Submission #1273316

#	Time	Username	Problem	Language	Result	Execution time	Memory
1273316		nlhuy	Knapsack (NOI18_knapsack)	C++20	100 / 100	107 ms	34112 KiB

knapsack

#include<bits/stdc++.h>
using namespace std;

#define ll long long
#define fi first
#define se second
#define Task "test"

typedef pair<int,int>ii;
typedef pair<ii,int>iii;

const int MOD = 1e9+7;
const int INF = 1e9+7;
const int Maxn = 1e5+7;
const int di[] = {0, 0, -1, 1};
const int dj[] = {-1, 1, 0, 0};

vector<ii>g[2007];
iii a[Maxn];
ll dp[2002][2002];

bool maximize(ll &x,const ll &y){
    if (x<y){
        x=y; return true;
    }
    return false;
}
bool cmp(ii i,ii j){
    return i.fi>j.fi;
}
void run_case(){
    int s,n;
    cin>>s>>n;
    for(int i=1;i<=n;i++) cin>>a[i].fi.fi>>a[i].fi.se>>a[i].se;
    for(int i=1;i<=n;i++){
        int t=a[i].fi.se;
        g[t].push_back({a[i].fi.fi,a[i].se});
    }
    for(int i=1;i<=s;i++) sort(g[i].begin(),g[i].end(),cmp);
    for(int i=1;i<=s;i++){
        for(int j=1;j<=s;j++){
            dp[i][j]=dp[i][j-1];
            int d=0;
            ll sum=0;
            for(ii x:g[j]){
                if (i-j*d<0) break;
                int k=x.se;
                for(int t=1;t<=k;t++){
                    d++;
                    if (i-j*d<0) break;
                    sum+=1LL*x.fi;
                    maximize(dp[i][j],dp[i-d*j][j-1]+sum);
                }
            }
        }
    }
    cout<<dp[s][s];
}
int main(){
    ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
    if (fopen(Task ".inp", "r"))
    {
        freopen(Task ".inp", "r", stdin);
        freopen(Task ".out", "w", stdout);
    }
    int t = 1;
    //cin >> t;
    while(t--){
        run_case();
    }
}

Compilation message (stderr)

knapsack.cpp: In function 'int main()':
knapsack.cpp:63:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   63 |         freopen(Task ".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
knapsack.cpp:64:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   64 |         freopen(Task ".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

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