Submission #1162376

#	Time	Username	Problem	Language	Result	Execution time	Memory
1162376		Alfraganus	Knapsack (NOI18_knapsack)	C++20	73 / 100	1095 ms	1608 KiB

knapsack

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

#define ll long long
#define str string
#define endl '\n'
#define fs first
#define ss second
#define all(a) a.begin(), a.end()

#define print(a) for(auto x : a) cout << x << ' '; cout << endl;
#define printmp(a) for(auto x : a) cout << x[0] << ' ' << x[1] << endl;

const int mod = 1e9 + 7;

struct SegTree {
    int size = 1;
    vector<int> tree;

    SegTree (vector<int> &a){
        while((int)a.size() > size)
            size <<= 1;
        tree.resize(size << 1);
        build(a, 0, 0, size);
    }

    void build(vector<int> &a, int x, int l, int r){
        if(r - l == 1){
            if(l < (int)a.size())
                tree[x] = a[l];
            return;
        }
        int mid = (l + r) >> 1;
        build(a, (x << 1) + 1, l, mid);
        build(a, (x << 1) + 2, mid, r);
        tree[x] = max(tree[(x << 1) + 1], tree[(x << 1) + 2]);
    }

    int get(int l, int r, int x, int lx, int rx){
        if(l <= lx and rx <= r)
            return tree[x];
        else if(r <= lx or rx <= l)
            return INT_MIN;
        int mid = (lx + rx) >> 1;
        return max(get(l, r, (x << 1) + 1, lx, mid), get(l, r, (x << 1) + 2, mid, rx));
    }

    int get(int l, int r){
        return get(l, r, 0, 0, size);
    }
};

void solve(){
    int s, n;
    cin >> s >> n;
    vector<int> v(n), w(n), k(n);
    for(int i = 0; i < n; i ++)
        cin >> v[i] >> w[i] >> k[i];
    vector<int> dp(s + 1);
    for(int i = 0; i < n; i ++){
        for(int j = 0; j < min(s + 1, w[i]); j ++){
            vector<int> a;
            for(int x = 0; x * w[i] + j <= s; x ++)
                a.push_back(dp[x * w[i] + j] - x * v[i]);
            SegTree st(a);
            for(int x = 0; x * w[i] + j <= s; x ++){
                int mx = st.get(max(0, x - k[i]), x + 1);
                dp[x * w[i] + j] = max(dp[x * w[i] + j], mx + x * v[i]);
            }
        }
    }
    cout << *max_element(all(dp));
}

signed main(){
    ios::sync_with_stdio(0);
    cin.tie(0), cout.tie(0);
    int t = 1;
    // cin >> t;
    while(t --){
        solve();
        cout << endl;
    }
}

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