Submission #469733

#	Time	Username	Problem	Language	Result	Execution time	Memory
469733		Yazan_Alattar	Knapsack (NOI18_knapsack)	C++14	100 / 100	321 ms	36320 KiB

knapsack

#include <iostream>
#include <fstream>
#include <vector>
#include <cstring>
#include <algorithm>
#include <set>
#include <map>
#include <queue>
#include <utility>
#include <cmath>
#include <numeric>
using namespace std;
typedef long long ll;
#define F first
#define S second
#define pb push_back
#define endl "\n"
#define all(x) x.begin(), x.end()
const int M = 2007;
const ll inf = 1e18;
const ll mod = 1e9 + 7;
const double pi = acos(-1);

vector < pair <ll,ll> > v[M];
ll n, s, dp[M][M];

int main()
{
    ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    cin >> s >> n;
    for(int i = 1; i <= n; ++i){
        ll val, w, k;
        cin >> val >> w >> k;
        v[w].pb({val, k});
    }
    for(int i = 1; i <= s; ++i){
        sort(all(v[i]), greater < pair <ll,ll> > ());
        ll w = 0, add = 0;
        for(auto k : v[i]){
            ll rem = k.S;
            while(rem--){
                w += i;
                add += k.F;
                if(w > s) break;
                for(int j = w; j <= s; ++j)
                    dp[j][i] = max(dp[j][i], dp[j - w][i - 1] + add);
            }
            if(w > s) break;
        }
        for(int j = 1; j <= s; ++j) dp[j][i] = max(dp[j][i], dp[j][i - 1]);
    }
    ll ans = 0;
    for(int i = 1; i <= 2000; ++i) ans = max(ans, dp[i][s]);
    cout << ans << endl;
    return 0;
}
// Don't forget special cases. (n = 1?)
// Look for the constraints. (Runtime array? overflow?)

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