Submission #531246

#	Time	Username	Problem	Language	Result	Execution time	Memory
531246		Netr	Knapsack (NOI18_knapsack)	C++14	100 / 100	485 ms	17504 KiB

knapsack

#include <bits/stdc++.h>
using namespace std;
typedef pair<int,int> pi;

#ifdef DEBUG
#define D(x...) printf(x);
#else
#define D(x...)
#endif

const int MAXS = 2005;
const int INF = 1<<30;

int S, N, dp[MAXS][MAXS];
vector<pi> items[MAXS];

int prefSum(int w, int k){
    
    int cnt = 0, val = 0;
    for(int i = items[w].size()-1; i >= 0; i--){
        if(cnt + items[w][i].second > k){
            val += (k - cnt) * items[w][i].first;
            cnt = k;
            break;
        }else{
            val += items[w][i].first * items[w][i].second;
            cnt += items[w][i].second;
        }
    }
    D("pS: %d, %d, val = %d\n", w, k, val);
    return val;
}

int solve(int w, int i){
    D("Solve: %d, %d\n", w, i);
    if(dp[w][i] > 0) return dp[w][i];
    if(w < 0) return -INF;
    if(i == 1) return prefSum(i, w);

    int res = solve(w, i-1);
    if(!items[i].empty()){
        for(int k = 1; k <= w/i; k++){
            res = max(res, prefSum(i,k) + solve(w-k*i, i-1));
        }
    }
    dp[w][i] = res;
    return res;
}

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    cin >> S >> N;
    for(int i = 0; i < N; i++){
        int vi, wi, ki;
        cin >> vi >> wi >> ki;
        items[wi].push_back({vi, ki});
    }
    for(int i = 0; i < MAXS; i++){
        sort(begin(items[i]), end(items[i]));
    }
    dp[S][S] = 0;
    cout << solve(S, S) << "\n";
}

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