Submission #1167264

#	Time	Username	Problem	Language	Result	Execution time	Memory
1167264		constnode	Knapsack (NOI18_knapsack)	C++20	73 / 100	1085 ms	456 KiB

knapsack

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int S, N;
    cin >> S >> N;
    
    // Use long long for dp to avoid overflow.
    vector<long long> dp(S + 1, 0);
    
    for (int i = 0; i < N; i++){
        long long v, w;
        long long k;
        cin >> v >> w >> k;
        
        // Binary splitting: decompose the k copies into groups.
        long long amount = 1;
        while (k > 0) {
            long long use = min(amount, k);
            long long weight = w * use;
            long long value  = v * use;
            
            // Process as a 0/1 knapsack item.
            for (int j = S; j >= weight; j--) {
                dp[j] = max(dp[j], dp[j - weight] + value);
            }
            
            k -= use;
            amount *= 2;
        }
    }
    
    cout << dp[S] << "\n";
    return 0;
}

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