Submission #890356

#	Time	Username	Problem	Language	Result	Execution time	Memory
890356		thunopro	Knapsack (NOI18_knapsack)	C++14	73 / 100	1091 ms	2904 KiB

knapsack

#include<bits/stdc++.h>
using namespace std ; 
#define maxn 300009 
#define ll long long 
#define fi first 
#define se second 
#define pb push_back 
#define left id<<1 
#define right id<<1|1
#define re exit(0);
#define _lower(v,x) lower_bound(v.begin(),v.end(),x)-v.begin()+1

const int mod = 1e9+7 ; 
const int INF = 1e9 ;
const int LOG = 18 ; 

typedef vector<int> vi ; 
typedef pair<int,int> pii ; 
typedef vector<pii> vii ;
typedef vector<ll> vl ;  
typedef pair<ll,ll> pll ; 
typedef vector<pll> vll ; 

void add ( int&a , int b ) { if ((a+=b) > mod ) a -= mod ; } 
void sub ( int&a , int b ) { if ((a-=b) < 0 ) a += mod ; } 
template<typename T> void chkmin(T& x, T y) {if(x > y) x = y;}
template<typename T> void chkmax(T& x, T y) {if(x < y) x = y;}

void rf ( ) 
{
	freopen ("bai1.inp","r",stdin) ; 
//	freopen ("bai1.out","w",stdout) ;
}

int _pow ( int a , int n ) 
{
	if ( n == 0 ) return 1 ; 
	int res = _pow ( a , n / 2 ) ; 
	if ( n % 2 ) return ( 1ll * res * res % mod * a % mod ) ; 
	else return ( 1ll * res * res % mod ) ; 
}

int n , s ; 
ll dp [maxn] ; 
void update ( ll x , ll w ) 
{
	for ( int i = s ; i >= x ; i -- ) chkmax (dp[i],dp[i-x]+w) ; 
}
int main ( ) 
{
	ios_base :: sync_with_stdio (0) ; 
	cin.tie(0) ; cout.tie(0) ;
//	rf () ; 
	cin >> s >> n ;
	
	memset ( dp , - 0x3f , sizeof dp ) ;
	dp [0] = 0 ; 
	 
	for ( int i = 1 ; i <= n ; i ++ ) 
	{
		int v , w , k ; 
		cin >> v >> w >> k ;
		int num = 1 ; 
		for ( int num = 1 ; num <= k ; num *= 2 ) update (1ll*num*w,1ll*num*v) , k -= num ;
		if ( k ) update (1ll*k*w,1ll*k*v) ;  
	}
	
	cout << *max_element (dp,dp+s+1) ; 
}




//-std=c++11

Compilation message (stderr)

knapsack.cpp: In function 'int main()':
knapsack.cpp:63:7: warning: unused variable 'num' [-Wunused-variable]
   63 |   int num = 1 ;
      |       ^~~
knapsack.cpp: In function 'void rf()':
knapsack.cpp:31:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   31 |  freopen ("bai1.inp","r",stdin) ;
      |  ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

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