Submission #983754

#	Time	Username	Problem	Language	Result	Execution time	Memory
983754		Peter2017	Knapsack (NOI18_knapsack)	C++14	0 / 100	2 ms	1884 KiB

knapsack

#include <bits/stdc++.h>
#define fi first
#define se second
#define ll long long
#define pii pair<int,int>
#define pll pair<ll,ll>
#define pill pair<int,ll>
#define mem(a, b) memset(a, b, sizeof(a))
#define MASK(i) (1LL << (i))
#define BIT(x, i) (((x) >> (i)) & 1)
#define name "test"

using namespace std;

const int N = 1e5 + 5;
const int S = 2e3 + 5;
const int mod = 1e9 + 7;

template <typename T1, typename T2> bool maxi(T1 &a, T2 b){if (a < b){a = b; return 1;} return 0;}
template <typename T1, typename T2> bool mini(T1 &a, T2 b){if (a > b){a = b; return 1;} return 0;}

struct item{
	int v, w, k;
};

int n;
int s;
ll f[2][S];
item a[N];
ll Max[S];
deque<ll> dq[S];

void load(){
	cin.tie(0)->sync_with_stdio(0);
	if (fopen(name".inp", "r")){
		freopen(name".inp", "r", stdin);
		freopen(name".out", "w", stdout);
	}
}

void input(){
	cin >> s >> n;
	for (int i = 1; i <= n; i++)
		cin >> a[i].v >> a[i].w >> a[i].k;
}

void solve(){
	for (int i = 1; i <= n; i++){
		bool cur = (i & 1);
		bool pre  = (cur ^ 1);
		for (int j = 0; j < a[i].w; j++){
			while (dq[j].size()) dq[j].pop_back();
			dq[j].push_back(j);
		}
		for (int j = a[i].w; j <= s; j++){
			int p = j % a[i].w;
			while (dq[p].size() && (j - dq[p].front()) / a[i].w > a[i].k) dq[p].pop_front();
			maxi(f[cur][j], f[pre][dq[p].back()] + ((j - dq[p].back()) / a[i].w) * a[i].v);
			maxi(f[cur][j], f[cur][j - 1]);
			while (dq[p].size()){
				int id = dq[p].back();
				if (f[pre][id] - ((id - p) / a[i].w) * a[i].v <= f[cur][j] - ((j - p) / a[i].w) * a[i].v) dq[p].pop_back();
				else break;
			}
			dq[p].push_back(j);
		}
	}
	cout << f[n & 1][s];
}

int main(){
	load();
	input();
	solve();
}

Compilation message (stderr)

knapsack.cpp: In function 'void load()':
knapsack.cpp:36:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   36 |   freopen(name".inp", "r", stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
knapsack.cpp:37:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   37 |   freopen(name".out", "w", stdout);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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