Submission #1319264

#	Time	Username	Problem	Language	Result	Execution time	Memory
1319264		mrbet	Knapsack (NOI18_knapsack)	C++20	100 / 100	37 ms	1880 KiB

knapsack

#include "bits/stdc++.h"
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

#define forr(_a,_b,_c) for(int _a = (_b); _a <= int (_c); ++_a)
#define ford(_a,_b,_c) for(int _a = (_b) + 1; _a --> int (_c);)
#define forf(_a,_b,_c) for(int _a = (_b); _a < int (_c); ++_a)
#define pb push_back
#define fi first
#define se second
#define vi vector
#define all(_v) _v.begin(), _v.end()
#define mask(_x) (1ll << (_x))
#define bit(_x,_y) (((_x) >> (_y)) & 1)
#define file "A"

string yes[2] = {"NO\n","YES\n"};
const ld eps = ld(1e-7);
const ll oo = ll(1e16) + 1;
const ll mod = ll(1e9) + 7;

template<class X, class Y>
inline bool Min(X &x, const Y &y) {
  if(x > y) {
    x = y;
    return true;
  }
  return false;
}

template<class X, class Y>
inline bool Max(X &x, const Y &y) {
  if(x < y) {
    x = y;
    return true;
  }
  return false;
}

const int N = 1e5+5;

int s,n;
ll dp[N];
vector<pii> items[N],newitems;
void solve() {
  cin>>s>>n;

  forr(i,1,n) {
    int v,w,a;
    cin>>v>>w>>a;
    items[w].pb({v,a});
  }

  forr(i,1,s) {
    if (items[i].size()==0) continue;
    sort(all(items[i]),greater<pii>());
    int d= s/i;

    for(pii x: items[i]) {
      if (d==0) break;
      forr(j,1,x.se) {
        if (d==0) break;
        newitems.pb({i,x.fi});
        d--;
      }
    }
  }

  for(pii x: newitems) {
    ford(i,s,x.fi) {
      dp[i]=max(dp[i],dp[i-x.fi]+x.se);
    }
  }
  cout<<dp[s];
  
}

void precalc() {
}

int main() {
  ios_base::sync_with_stdio(false); cin.tie(0);
  cout << fixed << setprecision(7);
  
  if (fopen(file".inp","r")) {
    freopen(file".inp","r",stdin); freopen(file".out","w",stdout);
  } 

  int tc = 1;
  //cin >> tc;
  precalc();
  while(tc--) {
    solve();
  }

  return 0;
}

Compilation message (stderr)

knapsack.cpp: In function 'int main()':
knapsack.cpp:89:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   89 |     freopen(file".inp","r",stdin); freopen(file".out","w",stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
knapsack.cpp:89:43: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   89 |     freopen(file".inp","r",stdin); freopen(file".out","w",stdout);
      |                                    ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

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