Submission #984309

#	Time	Username	Problem	Language	Result	Execution time	Memory
984309		duyanhloveav	Knapsack (NOI18_knapsack)	C++14	100 / 100	103 ms	29364 KiB

knapsack

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

using ll = long long;

const int mxn = 9 + 1e6;
const int inf = 0x3f3f3f3f;
const ll lnf = 0x3f3f3f3f3f3f3f3f;

vector<int> obj[mxn];

void SaKaTa(void) {
  int s, n;
  cin >> s >> n;
  for (int i = 1; i <= n; ++i) {
    int v, w, k;
    cin >> v >> w >> k;
    k = min(k, s / w);
    int tmp = 1;
    while (k) {
      int V = v * tmp, W = w * tmp;
      obj[W].push_back(V);
      k -= tmp;
      tmp = min(tmp * 2, k);
    }
  }
  vector<int> dp(s + 1);
  for (int i = 1; i <= s; ++i) {
    sort(begin(obj[i]), end(obj[i]), greater<int>());
    while ((int)obj[i].size() > (int) (s / i)) {
      obj[i].pop_back();
    }
    for (int v : obj[i]) {
      for (int w = s; w >= i; --w) {
        dp[w] = max(dp[w], dp[w - i] + v);
      }
    }
  }
  cout << *max_element(begin(dp), end(dp)) << "\n";
}

int32_t main(void) {
#define task "SaKaTa"
  cin.tie(0)->sync_with_stdio(0);
  for (string iext : {"in", "inp"}) {
    if (fopen((task "." + iext).c_str(), "r")) {
      freopen((task "." + iext).c_str(), "r", stdin);
      freopen(task ".out", "w", stdout);
    }
  }
  int testcase = 1;
  // cin >> testcase;
  while (testcase--) SaKaTa();
  return 0;
}

Compilation message (stderr)

knapsack.cpp: In function 'int32_t main()':
knapsack.cpp:47:14: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   47 |       freopen((task "." + iext).c_str(), "r", stdin);
      |       ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
knapsack.cpp:48:14: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   48 |       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