Submission #1146423

#	Time	Username	Problem	Language	Result	Execution time	Memory
1146423		CrabCNH	Knapsack (NOI18_knapsack)	C++20	100 / 100	38 ms	3056 KiB

knapsack

#include <bits/stdc++.h>

#define task   "BriantheCrab"

#define int    long long
#define pii    pair <int, int>
#define fi     first
#define se     second
#define szf    sizeof
#define sz(s)  (int)((s).size())

using namespace std;

template <class T> void mini (T &t, T f) {if (t > f) t = f;}
template <class T> void maxi (T &t, T f) {if (t < f) t = f;}

const int maxN = 1e5 + 5;
const int maxS = 2e3 + 5;
const int inf = 1e18 + 7;
const int mod = 1e9 + 7;

vector <pii> a[maxS];
int dp[maxN];

void solve () {
    int n, S;
    cin >> S >> n;
    for (int i = 1; i <= n; i ++) {
        int v, w, k;
        cin >> v >> w >> k;
        a[w].push_back ({v, k});
    }
    for (int w = 1; w <= S; w ++) {
        if (a[w].size () >= 1) {
            sort (a[w].rbegin (), a[w].rend ());
        }
    }
    for (int w = 1; w <= S; w ++) {
        int cnt = 0;
        for (auto [v, k] : a[w]) {
            for (int curK = 1; curK <= k && curK * w <= S; curK ++) {
                for (int j = S; j >= w; j -- ) {
                    maxi (dp[j], dp[j - w] + v);
                }
            }
            cnt += k;
            if (cnt > S / w) {
                break;
            }
        }
    }
    int res = 0;
    for (int i = 1; i <= S; i ++) {
        maxi (res, dp[i]);
    }
    cout << res;
    
}

signed main () {
    cin.tie (nullptr) -> sync_with_stdio (false);
    if (fopen (task".inp", "r")) {
        freopen (task".inp", "r", stdin);
        freopen (task".out", "w", stdout);
    }
    int t = 1;
    //cin >> t;
    while (t --) {
        solve ();
    } 
    return 0;
}
// thfdgb

Compilation message (stderr)

knapsack.cpp: In function 'int main()':
knapsack.cpp:63:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   63 |         freopen (task".inp", "r", stdin);
      |         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
knapsack.cpp:64:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   64 |         freopen (task".out", "w", stdout);
      |         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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