Submission #1047160

#	Time	Username	Problem	Language	Result	Execution time	Memory
1047160		Sharky	Knapsack (NOI18_knapsack)	C++17	100 / 100	76 ms	36568 KiB

knapsack

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

#define int long long

const int N = 2008;
vector<pair<int, int>> val[N];
int dp[N][N];

int32_t main() {
    ios::sync_with_stdio(0); cin.tie(0);
    int s, n;
    cin >> s >> n;
    for (int i = 1; i <= n; i++) {
        int v, w, k;
        cin >> v >> w >> k;
        if (w > s) continue;
        val[w].push_back({v, k});
    }
    for (int i = 1; i <= s; i++) {
        sort(val[i].begin(), val[i].end(), [] (auto x, auto y) {
            return x.first > y.first;
        });
        int threshold = s / i;
        vector<int> we;
        for (int j = 0; j < val[i].size(); j++) {
            int vv = val[i][j].first, sz = val[i][j].second;
            bool bad = 0;
            while (sz--) {
                if (we.size() >= threshold) {
                    bad = 1;
                    break;
                }
                we.push_back(vv);
            }
            if (bad) break;
        }
        for (int j = 0; j <= s; j++) dp[i][j] = dp[i - 1][j];
        for (int j = s; j >= i; j--) {
            int cnt = 0;
            int ps = 0;
            for (auto x : we) {
                cnt++;
                ps += x;
                if (j >= cnt * i) dp[i][j] = max(dp[i][j], dp[i - 1][j - cnt * i] + ps);
            }
        }
    }
    int mx = 0;
    for (int j = 1; j <= s; j++) for (int i = 1; i <= s; i++) mx = max(mx, dp[j][i]);
    cout << mx << '\n';
    return 0;
}

Compilation message (stderr)

knapsack.cpp: In function 'int32_t main()':
knapsack.cpp:26:27: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   26 |         for (int j = 0; j < val[i].size(); j++) {
      |                         ~~^~~~~~~~~~~~~~~
knapsack.cpp:30:31: warning: comparison of integer expressions of different signedness: 'std::vector<long long int>::size_type' {aka 'long unsigned int'} and 'long long int' [-Wsign-compare]
   30 |                 if (we.size() >= threshold) {
      |                     ~~~~~~~~~~^~~~~~~~~~~~

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