Submission #1050838

#	Time	Username	Problem	Language	Result	Execution time	Memory
1050838		trandangquang	Knapsack (NOI18_knapsack)	C++17	100 / 100	122 ms	51620 KiB

knapsack

#include <bits/stdc++.h>

using namespace std;

#define task "test"
#define FOR(i, a, b) for(int i = (a); i <= (b); ++i)
#define FORD(i, a, b) for(int i = (a); i >= (b); --i)
#define sz(a) (int)(a).size()
#define all(a) (a).begin(), (a).end()
#define bit(s, i) (((s) >> (i)) & 1)
#define ii pair <int, int>
#define vii vector <ii>
#define vi vector <int>
#define fi first
#define se second
#define ll long long
#define eb emplace_back
#define pb push_back
#define __builtin_popcount __builtin_popcountll

void solve();

int32_t main() {
    if(fopen(task".inp", "r")) {
		freopen(task".inp", "r", stdin);
		freopen(task".out", "w", stdout);
	}
	cin.tie(0)->sync_with_stdio(0);

    int tc = 1; // cin >> tc;
    FOR(i, 1, tc) {
        solve();
    }
}

const int N = 2e3+5;

int s, n, dp[N];
vii item;
vi weight[N];

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

    FOR(i, 1, n) {
        int v, w, k; cin >> v >> w >> k;
        FOR(j, 0, 30) if(k >= (1<<j)) {
            k -= (1<<j);
            int nww = min(1<<j, s/w)*w,
                nwv = min(1<<j, s/w)*v;

            item.eb(nww, nwv);
        }
        item.eb(min(k,s/w)*w, min(k,s/w)*v);
    }

    for(auto [w, v]:item) {
        weight[w].eb(v);
    }

    FOR(i, 1, s) {
        sort(all(weight[i]), greater <int>());
    }

    FOR(w, 1, s) {
        FOR(v, 0, sz(weight[w])-1) {
            if(v > s/w) break;
            FORD(j, s, w) {
                dp[j] = max(dp[j], dp[j-w] + weight[w][v]);
            }
        }
    }

    cout << dp[s];
}

Compilation message (stderr)

knapsack.cpp: In function 'int32_t main()':
knapsack.cpp:25:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   25 |   freopen(task".inp", "r", stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
knapsack.cpp:26:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   26 |   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