Submission #999388

#	Time	Username	Problem	Language	Result	Execution time	Memory
999388		GasmaskChan	Knapsack (NOI18_knapsack)	C++17	100 / 100	75 ms	36456 KiB

knapsack

#include <bits/stdc++.h>

using namespace std;
#define int long long
#define MAX 2005

int f[MAX][MAX];
map<int, vector<pair<int, int>>> a;
int32_t main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
//    freopen("test.inp", "r", stdin); freopen("test.out", "w", stdout);
    int s, n;
    cin >> s >> n;
    for (int v, w, k, i = 0; i < n; i++) {
        cin >> v >> w >> k;
        if (w <= s) {
            a[w].emplace_back(v, k);
        }
    }

    int i = 0;
    for (auto &[w, items] : a) {
        std::sort(items.begin(), items.end(), greater<pair<int, int>>());
        ++i;
        for (int j = 0; j <= s; j++) {
            f[i][j] = f[i - 1][j];
            int cur = 0, num = 0, take = 0, val = 0;
            while (cur < items.size() && (num + 1) * w <= j) {
                ++num;
                val += items[cur].first;
                f[i][j] = max(f[i][j], f[i - 1][j - num * w] + val);
                if (++take == items[cur].second) {
                    take = 0;
                    ++cur;
                }
            }
        }
    }

    cout << f[i][s];
    return 0;
}

Compilation message (stderr)

knapsack.cpp: In function 'int32_t main()':
knapsack.cpp:29:24: 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]
   29 |             while (cur < items.size() && (num + 1) * w <= j) {
      |                    ~~~~^~~~~~~~~~~~~~

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