Submission #990364

#	Time	Username	Problem	Language	Result	Execution time	Memory
990364		_rain_	Knapsack (NOI18_knapsack)	C++14	100 / 100	92 ms	6488 KiB

knapsack

/** author : Knquin_ **/
#include<bits/stdc++.h>
using namespace std;

using i64 = long long;
using ui64 = unsigned long long;

#define MASK(x) ((i64)(1) << (x))
#define BIT(mask , x) (((mask) >> (x)) & (1))
#define sz(x) (x).size()
#define all(x) (x).begin() , (x).end()

mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
template<class T>
    bool maximize(T &a , T b) {if (a < b) return a = b , true; else return false;}
template<class T>
    bool minimize(T &a , T b) {if (a > b) return a = b , true; else return false;}
template<class T>
    T gcd(T x , T y) {while (y) swap(y , x %= y); return x;}
template<class T>
    T lcm(T x , T y) {return (x * y) / gcd(x , y);}

template <class T> 
    void compress(vector<T> &a)
    {
        sort(a.begin() , a.end());
        a.resize(unique(a.begin() , a.end()) - a.begin());
        return;
    }
template<class T>
    void printArr(T& container , string separator = "" , string finish = "\n")
    {
        for (auto& item : container) cout << item << separator;
        cout << finish;
    }

const int maxn = 2e5;
const int maxww = 2e3;
int maxw , n;
int v[maxn + 2] , w[maxn + 2] , k[maxn + 2];

namespace subtask1
{
	bool condition(		)
	{
		return n <= 100;
	}
	i64 dp[102][maxww + 2];
	void cook(void)
	{
		i64 answer = 0;
		for (int i = 1; i <= n; ++i)
		{
			for (int turn = 0; turn <= min(k[i] , maxw / w[i]); ++turn)
			{
				for (int used = 0; used <= maxw - w[i] * turn; ++used)
					maximize(dp[i][used + w[i] * turn] , dp[i - 1][used] + (i64)v[i] * turn);
			}
		}
		for (int i = 0; i <= maxw; ++i)
			maximize(answer , dp[n][i]);
		cout << answer << '\n';
	}
}
namespace subtask2
{
	const int bestsize = 2e3 + 2;
	i64 dp[maxn + 2];
	vector<pair<int , int>> bucket[bestsize];

	void cook(void)
	{
		for (int i = 1; i <= n; ++i)
			bucket[w[i]].push_back({v[i] , k[i]});
		vector<pair<int , int>> opt;
		for (int i = 1; i <= maxw; ++i)
		{
			sort(all(bucket[i]));
			int canchoose = maxw / i;
			for (; canchoose && sz(bucket[i]); --canchoose)
			{
				bucket[i].back().second--;
				opt.push_back({bucket[i].back().first , i});
				if (!bucket[i].back().second) bucket[i].pop_back();
			}
		}
		dp[0] = 0;
		for(auto& des : opt)
		{
			for (int used = maxw - des.second; used >= 0; --used)
				maximize(dp[used + des.second] , dp[used] + des.first);
		}
		cout << *max_element(dp  , dp + maxw + 1);
	}
}

auto main(void)->int32_t
{
    cin.tie(nullptr)->sync_with_stdio(false);
    const string name = "main";
    if (fopen((name + ".inp").c_str() , "r"))
    {
        (void)!freopen((name + ".inp").c_str() , "r" , stdin);
        (void)!freopen((name + ".out").c_str() , "w+", stdout);
    }
    cin >> maxw >> n;
    for (int i = 1; i <= n; ++i) cin >> v[i] >> w[i] >> k[i];
    if (subtask1::condition()) 
    {
    	subtask1::cook();
    	return 0;
    }
    subtask2::cook();
}

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