Submission #997529

#	Time	Username	Problem	Language	Result	Execution time	Memory
997529		vjudge1	Knapsack (NOI18_knapsack)	C++17	100 / 100	91 ms	19540 KiB

knapsack

#include <bits/stdc++.h>
using namespace std;
signed main() {
    int S, N, W, v, n, ans = -1e18;
    cin >> S >> N;
    vector<vector<pair<int, int>>> w(S + 1);
    for (int i = 0; i < N; i++) {
        cin >> v >> W >> n;
        w[W].push_back({-v, n});
    }
    for (auto& i : w) {
        if (!i.size()) continue;
        sort(i.begin(), i.end());
    }
    vector<vector<int>> dp(S + 1, vector<int>(S + 1, -1e18));
    dp[0][0] = 0;
    for (int i = 1; i <= S; i++) {
        if (!w[i].size()) {
            dp[i] = dp[i - 1];
            continue;
        }
        for (int j = 0; j <= S; j++) {
            dp[i][j] = dp[i - 1][j];
            int a = 0;
            int ind = 0;
            int used = 0;
            int val = 0;
            while ((a + 1) * i <= j && ind < (int)w[i].size()) {
                a++;
                val += -w[i][ind].first;
                if (dp[i - 1][j - a * i] != -1e18) {
                    dp[i][j] = max(dp[i][j], dp[i - 1][j - a * i] + val);
                }
                ans = max(ans, dp[i][j]);
                used++;
                if (used == w[i][ind].second) {
                    used = 0;
                    ind++;
                }
            }
        }
    }
    if (ans < 0) ans = 0;
    cout << ans;
    return 0;
}

Compilation message (stderr)

knapsack.cpp: In function 'int main()':
knapsack.cpp:4:30: warning: overflow in conversion from 'double' to 'int' changes value from '-1.0e+18' to '-2147483648' [-Woverflow]
    4 |     int S, N, W, v, n, ans = -1e18;
      |                              ^~~~~
knapsack.cpp:15:54: warning: overflow in conversion from 'double' to 'std::vector<int>::value_type' {aka 'int'} changes value from '-1.0e+18' to '-2147483648' [-Woverflow]
   15 |     vector<vector<int>> dp(S + 1, vector<int>(S + 1, -1e18));
      |                                                      ^~~~~

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