Submission #683396

#	Time	Username	Problem	Language	Result	Execution time	Memory
683396		vjudge1	Knapsack (NOI18_knapsack)	C++17	100 / 100	128 ms	8988 KiB

knapsack

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

#define ll long long
#define ull unsigned long long
#define ed '\n'
#define pb push_back
#define int long long
#define ii pair<int,int>
#define o_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update>
#define fi first
#define se second

using namespace __gnu_pbds;
using namespace std;

int dp[2005];
vector<int> g[2005];

void solve() {
    int s, n;
    cin >> s >> n;

    while(n--) {
        int v, w, cnt;
        cin >> v >> w >> cnt;
        int tmp = 1;
        while(cnt) {
            int cv = v * min(tmp, cnt);
            int cw = w * min(tmp, cnt);

            if (cw <= s) g[cw].pb(cv);

            cnt -= min(tmp, cnt);
            tmp <<= 1;
        }
    }

    for(int i = 1; i <= s; ++i) {
        sort(g[i].begin(), g[i].end(), greater<int>());
        for(int k = 0; k < min(s / i, (int)g[i].size()); ++k) {
            int v = g[i][k];
            for(int j = s; j >= i; --j) dp[j] = max(dp[j], dp[j - i] + v);
        }
    }
    cout << dp[s];
}

signed main() {
    ios_base::sync_with_stdio(0); cin.tie(0);
    if (fopen("cf.inp", "r")) {
        freopen("cf.inp", "r", stdin);
        //freopen("cf.inp", "w", stdout);
    }
    solve();
    return 0;
}

Compilation message (stderr)

knapsack.cpp: In function 'int main()':
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("cf.inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

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