Submission #520472

#	Time	Username	Problem	Language	Result	Execution time	Memory
520472		nguyentu	Knapsack (NOI18_knapsack)	C++14	29 / 100	1 ms	332 KiB

knapsack

#include <bits/stdc++.h>

using namespace std;

#define int long long
#define ii pair<int , int>
#define v first
#define k second
#define inf (int) (1e9 + 7)

signed main() {
    ios_base::sync_with_stdio(0); cin.tie(NULL);cout.tie(NULL);
    int n , m; cin >> m >> n;
    vector<ii> a[m + 1];
    for (int i = 1 ; i <= n ; i++) {
        int v , w , k; cin >> v >> w >> k;
        a[w].push_back(ii(v , k));
    }
    vector<int> dp;
    dp.assign(m + 1 , -1);
    dp[0] = 0;
    for (int i = 1 ; i <= m ;i ++) {
        if (!a[i].size()) continue; 
        vector<int> f;
        f.assign(m + 1 , 0);
        sort(a[i].begin() , a[i].end() , greater<ii>());
        
        for (int j = i ; j <= m ; j++) {
            int cnt , sum , pos , total;
            cnt = sum = pos = total = 0;
            while (cnt <= j/i && pos < a[i].size()) {
                if (cnt + a[i][pos].k > j/i) {
                    int x = i*(j/i - cnt);
                    sum += x;
                    if (dp[j - sum] != -1)
                    f[j] = max({f[j] , dp[j] , dp[j - sum] + total + a[i][pos].v*(j/i - cnt)});
                    break;
                }
                else {
                    int x = i*a[i][pos].k;
                    sum += x;
                    cnt += a[i][pos].k;
                    total += a[i][pos].k*a[i][pos].v;
                    if (dp[j - sum] != -1)
                    f[j] = max({f[j] , dp[j] , dp[j - sum] + total});
                    pos++;
                }
            }
        }
        for (int j = i ; j <= m ; j++) {
            dp[j] = max(dp[j] , f[j]);
        }

    }
    int ans = 0;
    for (int i = 0 ; i <= m ; i++) {
         ans = max(ans , dp[i]);
         //cerr << dp[i] << " ";
    }
    cout << ans;
    return 0;
}

Compilation message (stderr)

knapsack.cpp: In function 'int main()':
knapsack.cpp:31:38: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   31 |             while (cnt <= j/i && pos < a[i].size()) {
      |                                  ~~~~^~~~~~~~~~~~~

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