Submission #1258258

#	Time	Username	Problem	Language	Result	Execution time	Memory
1258258		alizhan	Knapsack (NOI18_knapsack)	C++20	Compilation error	0 ms	0 KiB

knapsack

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

signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int s, n;
    cin >> s >> n;
    vector<pair<int, int>> items[2001];  

    for(int i = 0; i < n; i++) {
        int v, w, k;
        cin >> v >> w >> k;
        if(w <= s) items[w].push_back({v, k});
    }

    vector<int> dp(s + 1, INT_MIN);
    dp[0] = 0;
#include <bits/stdc++.h>
using namespace std;

signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int s, n;
    cin >> s >> n;
    vector<int> dp(s + 1, -1e18);
    vector<pair<int, int>> g[2010];  

    for(int i = 0; i < n; ++i) {
        int v, w, k;
        cin >> v >> w >> k;
        if(w <= s) {  
            g[w].push_back({v, k});
        }
    }

    for(int i = 1; i <= s; ++i) {
        sort(g[i].begin(), g[i].end(), greater<pair<int, int>>());
    }

    dp[0] = 0;  

    for(int i = 1; i <= s; ++i) {
        for(auto& item : g[i]) {
            int v = item.first;
            int k = item.second;
            int max_take = min(k, s / i);
            
            for(int x = 1; x <= max_take; ++x) {
                for(int j = s; j >= i; --j) {
                    if(dp[j - i] != -1e18) {
                        dp[j] = max(dp[j], dp[j - i] + v);
                    }
                }
            }
        }
    }

    int mx = 0;
    for(int i = 0; i <= s; ++i) {
        mx = max(mx, dp[i]);
    }
    cout << mx << endl;

    return 0;
}
    for(int w = 1; w <= s; w++) {
        for(auto [v, k] : items[w]) {
            for(int p = 1; k > 0; p *= 2) {
                int take = min(p, k);
                for(int j = s; j >= w * take; j--) {
                    if(dp[j - w * take] != INT_MIN) {
                        dp[j] = max(dp[j], dp[j - w * take] + v * take);
                    }
                }
                k -= take;
            }
        }
    }

    cout << max(0, *max_element(dp.begin(), dp.end())) << endl;
}

Compilation message (stderr)

knapsack.cpp: In function 'int main()':
knapsack.cpp:23:12: warning: empty parentheses were disambiguated as a function declaration [-Wvexing-parse]
   23 | signed main() {
      |            ^~
knapsack.cpp:23:12: note: remove parentheses to default-initialize a variable
   23 | signed main() {
      |            ^~
      |            --
knapsack.cpp:23:12: note: or replace parentheses with braces to value-initialize a variable
knapsack.cpp:23:15: error: a function-definition is not allowed here before '{' token
   23 | signed main() {
      |               ^