Submission #633130

#	Time	Username	Problem	Language	Result	Execution time	Memory
633130		Alma	Knapsack (NOI18_knapsack)	C++17	0 / 100	97 ms	262144 KiB

knapsack

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

#define fi first
#define se second
using ll = long long;
using ii = pair<int,int>;

const int INF = 1e9;
const ll LLINF = 1e18;
using vi = vector<int>;
using vvi = vector<vi>;

void setIO (string fileName) {
    ios::sync_with_stdio(false);
    cin.tie(NULL);
    if (fileName != "std") {
        freopen((fileName + ".in").c_str(), "r", stdin);
        freopen((fileName + ".out").c_str(), "w", stdout);
    }
}

const int MX = 100'005;
int S, N;
int v[MX], w[MX], k[MX];
ll DP[MX][2'005];

ll knapsack (int i, int rem) {
	if (i == N or rem == 0) return 0;
	ll &ans = DP[i][rem];
	if (ans != -1) return ans;
	if (rem < w[i]) return ans = knapsack(i+1, rem);
	for (int x = 0; x <= k[i] and rem >= w[i]*x; x++) {
		ans = max(ans, v[i]*x + knapsack(i+1, rem - w[i]*x));
	}
	return ans;
}

int main() {
    setIO("std");

	cin >> S >> N;
	for (int i = 0; i < N; i++) {
		cin >> v[i] >> w[i] >> k[i];
		k[i] = min(k[i], S / w[i]);
	}
	memset(DP, -1, sizeof DP);
	cout << knapsack(0, S) << '\n';

    return 0;
}

Compilation message (stderr)

knapsack.cpp: In function 'void setIO(std::string)':
knapsack.cpp:18:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   18 |         freopen((fileName + ".in").c_str(), "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
knapsack.cpp:19:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   19 |         freopen((fileName + ".out").c_str(), "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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