Submission #522844

#	Time	Username	Problem	Language	Result	Execution time	Memory
522844		exopeng	Knapsack (NOI18_knapsack)	C++14	100 / 100	509 ms	258880 KiB

knapsack

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

#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
template <class T> using Tree = tree<T, null_type, less<T>,
rb_tree_tag, tree_order_statistics_node_update>;

#define mp make_pair
#define pb push_back
#define lb lower_bound
#define ub upper_bound
#define f first
#define ll long long
#define s second
#define pii pair<int,int>
#define pdd pair<double,double>
#define pll pair<ll,ll>
#define is insert
const long long INF = 1e9;
const long long MOD = 1e9+7;
const int MAXN = 2e5;
//store test cases here
/*
15 5
4 12 1
2 1 1
10 4 1
1 1 1
2 2 1

20 3
5000 15 1
100 1 3
50 1 4
*/
int s,n;
//weight, value
vector<pii> ar;
//vallue, occurences
vector<pii> wg[MAXN];
//max value after considering first j items with total weight i
ll dp[2002][16000];

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cin>>s>>n;
    for(int i=0;i<n;i++){
        int v,w,k;cin>>v>>w>>k;
        wg[w].pb(mp(v,k));
    }
    for(int i=1;i<=s;i++){
        sort(wg[i].begin(),wg[i].end());
        reverse(wg[i].begin(),wg[i].end());
        int ct=0;
        int ix=0;
        while(ct<s/i){
            while(ix<wg[i].size()&&wg[i][ix].s==0){
                ix++;
            }
            if(ix==wg[i].size()){
                break;
            }
            ct++;
            ar.pb(mp(i,wg[i][ix].f));
            wg[i][ix].s--;
        }
    }
    ll as=0;
    for(int i=0;i<=ar.size();i++){
        for(int j=0;j<=s;j++){
            if(i){
                dp[j][i]=max(dp[j][i],dp[j][i-1]);
            }
            if(i<ar.size()&&ar[i].f+j<=s){
                dp[ar[i].f+j][i+1]=max(dp[ar[i].f+j][i+1],dp[j][i]+ar[i].s);
            }
        }
    }
    cout<<dp[s][ar.size()]<<'\n';

    return 0;
}

Compilation message (stderr)

knapsack.cpp: In function 'int main()':
knapsack.cpp:60:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   60 |             while(ix<wg[i].size()&&wg[i][ix].s==0){
      |                   ~~^~~~~~~~~~~~~
knapsack.cpp:63:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   63 |             if(ix==wg[i].size()){
      |                ~~^~~~~~~~~~~~~~
knapsack.cpp:72:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   72 |     for(int i=0;i<=ar.size();i++){
      |                 ~^~~~~~~~~~~
knapsack.cpp:77:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   77 |             if(i<ar.size()&&ar[i].f+j<=s){
      |                ~^~~~~~~~~~
knapsack.cpp:71:8: warning: unused variable 'as' [-Wunused-variable]
   71 |     ll as=0;
      |        ^~

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