Submission #1000200

#	Time	Username	Problem	Language	Result	Execution time	Memory
1000200		Icelast	Knapsack (NOI18_knapsack)	C++17	100 / 100	48 ms	8532 KiB

knapsack

#include <iostream>
#include <bits/stdc++.h>
#define ll long long
using namespace std;
const ll maxn = 2*1e5+5, INF = 4e18+9;
struct item{
    ll v, w, k;
};
bool cmpv(item a, item b){
    return a.v > b.v;
}
void solve(){
    ll S, n;
    cin >> S >> n;
    vector<item> a(n+1);
    for(int i = 1; i <= n; i++){
        cin >> a[i].v >> a[i].w >> a[i].k;
    }
    vector<vector<item>> g(2001);
    for(int i = 1; i <= n; i++){
        g[a[i].w].push_back(a[i]);
    }
    vector<ll> dp(S+1, -INF);
    dp[0] = 0;
    auto add = [&](vector<ll> &f, item a) -> void{
        for(int i = S; i >= 0; i--){
            if(i-a.w >= 0) f[i] = max(f[i], f[i-a.w]+a.v);
        }
    };
    for(int i = 1; i <= 2000; i++){
        sort(g[i].begin(), g[i].end(), cmpv);
        ll it = 0, cnt = 0;
        if((int)g[i].size() == 0) continue;
        for(int j = 1; j <= S/i; j++){
            cnt++;
            if(cnt > g[i][it].k){
                cnt = 1;
                it++;
            }
            if(it >= (int)g[i].size()) break;
            add(dp, g[i][it]);
        }
    }
    ll ans = -1;
    for(int i = 0; i <= S; i++) ans = max(ans, dp[i]);
    cout << ans;
}
int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    solve();
}

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