Submission #1344761

#	Time	Username	Problem	Language	Result	Execution time	Memory
1344761		29avaz	Knapsack (NOI18_knapsack)	C++20	100 / 100	371 ms	18812 KiB

knapsack

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

int s, n;

struct items{
    int v, w, k;
}item[100005];

int dp[100005][2005];

int main() {
    scanf("%d %d", &s, &n);

    set<int> weight;
    for (int i = 0; i < n; i++) {
        scanf("%d %d %d", &item[i].v, &item[i].w, &item[i].k);
        weight.insert(item[i].w);
    }
    
    map<int, vector<pair<int, int>>> a; // group by weight
    for (int i = 0; i < n; i++) {
        a[item[i].w].push_back({item[i].v, item[i].k});
    }

    for (int i = 1; i <= weight.size(); i++) {
        int w = *next(weight.begin(), i - 1);
        sort(a[w].begin(), a[w].end(), greater<pair<int, int>>());
        for (int j = 0; j <= s; j++) {
            dp[i][j] = dp[i - 1][j];

            long long w_sum = 0, v_sum = 0;
            int used = 0;
            int num = 0;
            while (num < a[w].size() && (w_sum + w) <= j) {
                w_sum += w;
                v_sum += a[w][num].first;

                dp[i][j] = max(dp[i][j], dp[i - 1][j - w_sum] +(int)v_sum);

                used++;
                if (used >= a[w][num].second) {
                    used = 0;
                    num++;
                }
            }
        }
    }

    int ans = 0;
    for(int i = 1; i <= weight.size(); i++) {
        for (int j = 0; j <= s; j++) {
            ans = max(ans, dp[i][j]);
        }
    }
    printf("%d", ans);
    return 0;
} 

Compilation message (stderr)

knapsack.cpp: In function 'int main()':
knapsack.cpp:13:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   13 |     scanf("%d %d", &s, &n);
      |     ~~~~~^~~~~~~~~~~~~~~~~
knapsack.cpp:17:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   17 |         scanf("%d %d %d", &item[i].v, &item[i].w, &item[i].k);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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