Submission #551921

#	Time	Username	Problem	Language	Result	Execution time	Memory
551921		training4usaco	Knapsack (NOI18_knapsack)	C++11	100 / 100	116 ms	3708 KiB

knapsack

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

#define pii pair<int, int>
#define fi first
#define se second
#define INF 1000000009

#define MAXS 2005

vector<pii> weightgroup[MAXS];
int dp[MAXS];
 
bool comp(pii a, pii b) {
    return a.fi > b.fi;
}
 
int main() {
    int s, n;
    cin >> s >> n;
 
    for(int i = 0; i < n; ++i) {
        int v, w, k;
        cin >> v >> w >> k;
        weightgroup[w].push_back(make_pair(v, k));
    }
 
    for(int i = 1; i <= s; ++i) {
        sort(weightgroup[i].begin(), weightgroup[i].end(), comp);
    }
 
    for(int i = 0; i <= s; ++i) {
        dp[i] = -INF;
    }

    dp[0] = 0;
 
    for(int i = 1; i <= s; ++i) {
        int usedspace = 0;
        for(pii item : weightgroup[i]) {
            for(int c = 1; c <= item.se; ++c) {
                usedspace += i;
                for(int leftover = s; leftover >= usedspace; --leftover) {
                    dp[leftover] = max(dp[leftover], dp[leftover - i] + item.fi);
                }
                if(usedspace > s) {
                    break;
                }
            }
            if(usedspace > s) {
                break;
            }
        }
    }
 
    int answer = 0;
    for(int i = 1; i <= s; ++i) {
        answer = max(answer, dp[i]);
    }
    cout << answer << endl;
}

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