Submission #1267090

#	Time	Username	Problem	Language	Result	Execution time	Memory
1267090		minhmc2019	Knapsack (NOI18_knapsack)	C++17	73 / 100	1093 ms	444 KiB

knapsack

#include <bits/stdc++.h>
#define FOR(i, l, r, x) for(int i = l; i <= r; i += x)
#define FOD(i, l, r, x) for(int i = l; i >= r; i -= x)
#define debug(x) cout << "[DEBUG]:  " << #x << " = " << x << endl;
#define _double_vector_ vector<vector<int>>
#define BIT(x) (1 << (x))
#define pii pair<int, int>
#define fi first
#define se second
//#define int long long
using namespace std;

const int N = 5e6 + 5;
const int mod = 1e9 + 7;

int S, n, dp[2005];
vector <pii> items;

void solve() {
    cin >> S >> n; items.reserve(N);
    FOR(_, 1, n, 1) {
        int v, w, k; cin >> v >> w >> k;
        int lim = min(S / w, k);

        if (lim == 0) continue;

        int tmp = __lg(lim);

        FOR(i, 0, tmp, 1) {
            int mul = min(BIT(i), k);
            int cur_v = v * mul;
            int cur_w = w * mul;

            FOD(k, S, 0, 1) {
                if (k >= cur_w) {
                    dp[k] = max(dp[k], dp[k - cur_w] + cur_v);
                }
            }

            k -= mul;

            if (k == 0) break;
        }
    }

    cout << dp[S] << '\n';
}

signed main() {
    #define name "task"
    if (ifstream(name".inp")) {
        freopen(name".inp", "r", stdin);
        freopen(name".out", "w", stdout);
    }

    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    solve();
}

Compilation message (stderr)

knapsack.cpp: In function 'int main()':
knapsack.cpp:52:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   52 |         freopen(name".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
knapsack.cpp:53:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   53 |         freopen(name".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 12 / 12
• Subtask 2: 17 / 17
• Subtask 3: 20 / 20
• Subtask 4: 24 / 24
• Subtask 5: 0 / 27