Submission #806833

#	Time	Username	Problem	Language	Result	Execution time	Memory
806833		loveubota	Knapsack (NOI18_knapsack)	C++17	100 / 100	584 ms	6176 KiB

knapsack

// In the name of God
#include <bits/stdc++.h>
using namespace std ;
 
#define ll long long
#define pb push_back
#define ld long double
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define remove(x) x.erase(unique(all(x)), x.end())
 
#define rep(i, a, b) for (int i = (a); i <= (b); i++)
#define per(i, b, a) for (int i = (b); i >= (a); i--)
 
const int N = 1e5 + 1 , inf = (1 << 30) , L = 20 ;
const ld eps = 1e-6 ;
const ll INF = 1e18 + 123 , mod = 1e9 + 7 ;
 
int s , n , v[N] , w[N] , k[N] ;
vector<vector<ll>> dp ;
 
ll go(int i , int j) {
	if (i > n) return 0 ;
  if (~dp[i][j]) return dp[i][j] ;
	ll ans = 0 ;
	rep(c, 0, k[i]) {
		if (c * w[i] > j) break ;
		ans = max(ans , go(i + 1, j - (1ll * c * w[i])) + 1ll * c * v[i]) ;
	}
	dp[i][j] = ans ;
 
	return ans ;
}
 
/*
 
15 5
4 12 1
2 1 1
10 4 1
1 1 1
2 2 1
	
*/
 
void solve(int &tc) {
	cin >> s >> n ;
	rep(i , 1 , n) {
		cin >> v[i] >> w[i] >> k[i] ;
	}
    if (n <= 100 && s <= 2000) {
        dp = vector<vector<ll>>(n + 1, vector<ll>(s + 1, -1)) ;
	    cout << go(1,s) ;
    } else {
       vector<pair<ll,ll>> obj[s + 1];
    long long dp1[2001];
    memset(dp1, 0, sizeof dp1);
    for (int i = 1; i <= n; i++) {
      obj[w[i]].pb({v[i], k[i]});
    }
 
    for (int i = 0; i <= s; i++) {
      if (obj[i].size() == 0) continue;
      sort(all(obj[i]), greater<pair<int, int>>());
 
      int id = 0;
      for (int j = 0; j * i < s; j++) {
        if (id >= obj[i].size()) break;
        for (int k = s; k >= i; k--) {
          dp1[k] = max(dp1[k], dp1[k - i] + obj[i][id].first);
        }
        --obj[i][id].second;
        if (obj[i][id].second == 0) ++id;
      }
    }
    cout << dp1[s] << endl;
    }
    return ;
}
 
int main() {
#ifdef ONPC
	freopen("inp", "r", stdin) ;
#endif
    ios_base::sync_with_stdio(false) ;
    cin.tie(0) ;
	int T = 1 ;
    // cin >> T ;
    rep(i, 1 ,T) {
        solve(i) ;
    }
	return 0;
}

Compilation message (stderr)

knapsack.cpp: In function 'void solve(int&)':
knapsack.cpp:68:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   68 |         if (id >= obj[i].size()) break;
      |             ~~~^~~~~~~~~~~~~~~~

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