Submission #467858

#	Time	Username	Problem	Language	Result	Execution time	Memory
467858		rainliofficial	Knapsack (NOI18_knapsack)	C++17	12 / 100	1 ms	332 KiB

knapsack

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

struct Item{
    int v, w, k;
    bool operator<(const Item& o) const{
        return v < o.v;
    };
};

const int MAXN = 1e5 + 5, MAXS = 2000 + 5;
int maxW, n;
map<int, vector<Item>> arr;
ll dp[MAXS], pdp[MAXS];
int main(){
    cin.tie(0)->sync_with_stdio(0);
    //freopen("file.in", "r", stdin);
    cin >> maxW >> n;
    for (int i=0; i<n; i++){
        int v, w, k;
        cin >> v >> w >> k;
        if (arr.find(w) == arr.end()){
            arr.insert({w, vector<Item>()});
        }
        arr[w].push_back({v, w, k});
    }
    for (auto currW : arr){
        vector<Item> curr = currW.second;
        sort(curr.begin(), curr.end());
        int iters = maxW/currW.first;
        for (int j=0; j<iters && j < curr.size(); j++){
            Item currItem = curr[j];
            for (int i=1; i<=maxW; i++){
                dp[i] = pdp[i];
                for (int k=1; currItem.w*k<=i && k <= currItem.k; k++){
                    if (i >= (long)currItem.w*k){
                        dp[i] = max(dp[i], pdp[i-currItem.w*k] + (long)currItem.v*k);
                    }
                }
            }
            for (int k=0; k<=maxW; k++){
                pdp[k] = dp[k];
                dp[k] = 0;
            }
        }
    }
    cout << pdp[maxW] << '\n';
}   

Compilation message (stderr)

knapsack.cpp: In function 'int main()':
knapsack.cpp:32:36: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<Item>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   32 |         for (int j=0; j<iters && j < curr.size(); j++){
      |                                  ~~^~~~~~~~~~~~~

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