Submission #1003131

#	Time	Username	Problem	Language	Result	Execution time	Memory
1003131		fryingduc	Knapsack (NOI18_knapsack)	C++17	100 / 100	292 ms	5108 KiB

knapsack

// #pragma GCC optimize("Ofast,unroll-loops")
#include "bits/stdc++.h"
using namespace std;
 
#define sz(a) ((int)(a).size())
#define all(a) (a).begin(), (a).end()
 
#define yes cout << "YES\n"
#define no cout << "NO\n"
 
#ifdef LOCAL
#define debug(val) cerr << "["#val << " = " << (val) << "] "
#define slash() cerr << "\n-----------\n"
#define time() cerr << "Time is: " << 1000 * clock()/CLOCKS_PER_SEC << " ms\n"
#else
#define debug(val) 1407
#define slash() 1407
#define time() 1407
#endif
 
const string filename = "";
 
void IO(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    if(filename.size()){
        string in = filename + ".inp";
        string out = filename + ".out";
        freopen(in.c_str(), "r", stdin);
        freopen(out.c_str(), "w", stdout);
    }
}
int n, W;
vector<pair<long long, long long>> item[2005];
long long f[2005];
void solve(){
    cin >> W >> n;
    for(int i=0;i<n;i++){
        int v, w, k; cin >> v >> w >> k;
        item[w].push_back({v, k});
    }
    for(int i = 1; i <= W; ++i) {
        sort(item[i].begin(), item[i].end(), greater<pair<int, int>>());
        for(int j = W; j >= 0; --j) {
            int cur = 0;
            long long sum = 0;
            for(int k = 0; k < (int)item[i].size(); ++k) {
                for(int l = 0; l < item[i][k].second; ++l) {
                    ++cur;
                    sum = sum + item[i][k].first;
                    if(j < cur * i) break;
                    f[j] = max(f[j], f[j - cur * i] + sum);
                }
            }
        }
    }
    cout << *max_element(f + 1, f + W + 1);
}
signed main(){
    IO();
	int test = 1;
	/* cin >> test; */
	for(int i=1;i<=test;i++){
		// cout << "Case " << "#" << i << ": ";
		solve();
	}
	return 0;
}

Compilation message (stderr)

knapsack.cpp: In function 'void IO()':
knapsack.cpp:29:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   29 |         freopen(in.c_str(), "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
knapsack.cpp:30:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   30 |         freopen(out.c_str(), "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

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