Submission #1101116

#	Time	Username	Problem	Language	Result	Execution time	Memory
1101116		KindaGoodGames	Knapsack (NOI18_knapsack)	C++14	100 / 100	85 ms	8888 KiB

knapsack

#include<bits/stdc++.h>

#define ll long long
#define int ll
#define pii pair<int,int>
#define tiii tuple<int,int,int>

using namespace std;

const ll INF = numeric_limits<ll>::max() / 2;
int32_t main() {
    int s, n;
    cin >> s >> n;
    //vector<tiii> items(n);
    vector<vector<tiii>> itemsPerWeight(s + 1);
    for (int i = 0; i < n; i++) {
        int v, w, k;
        cin >> v >> w >> k;
        //items[i] = {v, w, k};
        if (w <= s) itemsPerWeight[w].push_back({ v, w, k });
    }

    vector<int> dp(s + 1, -INF);
    dp[0] = 0;

    // iterate through each block
    for (int i = 1; i <= s; i++) {
        // generate the block for this weight
        priority_queue<pii> pq;
        for (auto p : itemsPerWeight[i]) {
            pq.push({ get<0>(p), get<2>(p) });
        }
        vector<int> values;
        values.push_back(0);
        for (int k = 1; k <= s / i; k++) {
            if (pq.empty()) break;
            auto p = pq.top();
            pq.pop();
            values.push_back(values[k - 1] + p.first);
            if (p.second > 1) pq.push({ p.first,p.second-1 });
        }

        // do dp transitions
        for (int k = s; k > 0; k--) {
            for (int j = 0; j < values.size(); j++) {
                if (k - (j * i) < 0) break;
                dp[k] = max(dp[k], dp[k - (j * i)] + values[j]);
            }
        }
    }
    int ma = 0;
    for (int i = 0; i <= s; i++) {
        ma = max(ma, dp[i]);
    }
    cout << ma << endl;
}

Compilation message (stderr)

knapsack.cpp: In function 'int32_t main()':
knapsack.cpp:45:31: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   45 |             for (int j = 0; j < values.size(); j++) {
      |                             ~~^~~~~~~~~~~~~~~

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