Submission #1201576

#	Time	Username	Problem	Language	Result	Execution time	Memory
1201576		spampots	Knapsack (NOI18_knapsack)	C++20	73 / 100	1095 ms	328 KiB

knapsack

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

typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<pii> vpii;

const int MOD = 1e9 + 7;
const int INF = INT_MAX;
const ll LINF = LLONG_MAX;

#define fast ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL)

#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define all(v) v.begin(), v.end()
#define rep(i, a, b) for(int i = a; i < b; ++i)

void solve() {
    int s, n;
cin >> s >> n;
vector<int> dp(s + 1, 0);

for (int i = 0; i < n; ++i) {
    int v, w, k;
    cin >> v >> w >> k;

    if (1LL * k * w >= s) {
        // Unbounded knapsack
        for (int j = w; j <= s; ++j)
            dp[j] = max(dp[j], dp[j - w] + v);
    } else {
        // Bounded knapsack with binary trick
        for (int c = 1; k > 0; c <<= 1) {
            int cnt = min(c, k);
            int wt = cnt * w;
            int val = cnt * v;
            for (int j = s; j >= wt; --j)
                dp[j] = max(dp[j], dp[j - wt] + val);
            k -= cnt;
        }
    }
}

int ans = *max_element(dp.begin(), dp.end());
cout << ans << "\n";
}

int main() {
    fast;

    int t = 1;
    while(t--) {
        solve();
    }

    return 0;
}

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