Submission #733513

#	Time	Username	Problem	Language	Result	Execution time	Memory
733513		chanhchuong123	Knapsack (NOI18_knapsack)	C++14	100 / 100	59 ms	3892 KiB

knapsack

#include <bits/stdc++.h>
using namespace std;
#define task ""
#define fi first
#define se second
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define FOR(i, a, b) for (int i = (a), _b = (b); i <= _b; ++i)
#define FORD(i, a, b) for (int i = (b), _a = (a); i >= _a; --i)

template <typename T1, typename T2> bool minimize(T1 &a, T2 b) {
	if (a > b) {a = b; return true;} return false;
}
template <typename T1, typename T2> bool maximize(T1 &a, T2 b) {
	if (a < b) {a = b; return true;} return false;
}

const int dx[] = {-1, 0, 0, +1};
const int dy[] = {0, -1, +1, 0};

const int MAX = 2020;
int S, N, dp[MAX];
vector<pair<int, int>> a;
vector<pair<int, int>> v[MAX];

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

	if (fopen(task".inp", "r")) {
		freopen(task".inp", "r", stdin);
		freopen(task".out", "w", stdout);
	}

	cin >> S >> N;
	for (int i = 1; i <= N; ++i) {
        int V, W, K; cin >> V >> W >> K;
        v[W].push_back({V, K});
	}
	for (int i = 1; i <= 2000; ++i) {
        sort(all(v[i]));
        int maxPro = S / i;
        while (maxPro > 0 && v[i].size()) {
            a.push_back({v[i].back().fi, i}); --maxPro;
            if (!(--v[i].back().se)) v[i].pop_back();
        }
	}
	for (pair<int, int> &x: a) {
        for (int j = S; j >= x.se; --j)
            maximize(dp[j], dp[j - x.se] + x.fi);
	}
	cout << *max_element(dp, dp + S + 1);
	return 0;
}

Compilation message (stderr)

knapsack.cpp: In function 'int main()':
knapsack.cpp:31:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   31 |   freopen(task".inp", "r", stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
knapsack.cpp:32:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   32 |   freopen(task".out", "w", stdout);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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