Submission #1192956

#	Time	Username	Problem	Language	Result	Execution time	Memory
1192956		euclid	Knapsack (NOI18_knapsack)	C++20	49 / 100	24 ms	32328 KiB

knapsack

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
#define pb push_back
#define fi first
#define se second
#define vi vector<int>
#define pii pair<int, int>
#define pll pair<ll, ll>
#define vl vector<ll>

int n, s;
const int MN = 1e5 + 3, MS = 2003;
ll v[MN], w[MN], k[MN];
vi weight[MS]; //weight[i] - all (up to 2000) items with weight i sorted in decreasing value
ll dp[MS][MS], pref[MS][MS];

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    cin >> s >> n;
    for(int i = 1; i <= n; i++) cin >> v[i] >> w[i] >> k[i];
    for(int i = 1; i <= n; i++) {
        if(weight[w[i]].size() == 2000) continue;
        for(int j = 1; j <= min(k[i], (ll)2000-(ll)weight[w[i]].size()); j++)
            weight[w[i]].pb(v[i]);
    }
//    cout << weight[15].size() << '\n';
//    cout << weight[1].size() << '\n';
    for(int i = 1; i < MS; i++) {
        assert(weight[i].size() <= 2000);
        sort(weight[i].begin(), weight[i].end(), greater<>());
        for(int j = 0; j < weight[i].size(); j++) {
            pref[i][j] = weight[i][j];
            if(j != 0) pref[i][j] += pref[i][j-1];
        }
    }
    for(int i = 1; i < MS; i++) {
        for(int j = 1; j <= s; j++) {
            dp[i][j] = max(dp[i][j], dp[i-1][j]);
            for(int x = 1; x*i <= j && x <= weight[i].size(); x++) {
                dp[i][j] = max(dp[i][j], dp[i-1][j-x*i]+pref[i][x-1]);
            }
        }
    }
    cout << dp[MS-1][s] << '\n';

//    20 3
//    5000 15 1
//    100 1 3
//    50 1 4

}

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