Submission #875104

#	Time	Username	Problem	Language	Result	Execution time	Memory
875104		saturina	Knapsack (NOI18_knapsack)	C++14	100 / 100	64 ms	4044 KiB

knapsack

#include<bits/stdc++.h>
using namespace std;
//#define int long long
#define ar array
const int mxn = 1e6 + 5;
int s,dp[2005],n;
map<int,vector<pair<int,int>>> mp;
vector<ar<int,3>> vt(1);
int32_t main() {
    cin.tie(0)->sync_with_stdio(0);
    cin >> s >> n;
    for(int i = 1;i <= n;i++) {
        int v,w,k;
        cin >> v >> w >> k;
        if(w > s || k <= 0) continue;
        ar<int,3> arr;
        arr[0] = v,arr[1] = w,arr[2] = k;
        //vt.push_back(arr);
        mp[w].push_back({v,k});
    }
    for(auto x : mp) {
        sort(x.second.begin(),x.second.end(), greater<pair<int,int>> ());
        int limit = (s/x.first) + 2,cnt = 0,itr = 0;
        while(cnt <= limit && itr < x.second.size()) {
            if(cnt + x.second[itr].second <= limit) {
                vt.push_back({x.second[itr].first , x.first , x.second[itr].second});
                cnt += x.second[itr].second;
                itr++;
            }
            else {
                if(cnt == limit) break;
                vt.push_back({x.second[itr].first , x.first , limit - cnt});
                break;
            }
        }
    }
    n = vt.size() - 1;
    for(int i = 1;i <= n;i++) {
        int v = vt[i][0] , w = vt[i][1] , k = vt[i][2];
        for(int j = s;j >= 0;j--) {
            for(int t = 1;t * w <= j && t <= k;t++) {
                if(dp[j - t * w] + t * v >= dp[j]) dp[j] = dp[j - t * w] + t * v;
            }
        }
    }
    cout << dp[s] << '\n';
    return 0;
}

Compilation message (stderr)

knapsack.cpp: In function 'int32_t main()':
knapsack.cpp:24:35: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   24 |         while(cnt <= limit && itr < x.second.size()) {
      |                               ~~~~^~~~~~~~~~~~~~~~~

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