Submission #1030367

#	Time	Username	Problem	Language	Result	Execution time	Memory
1030367		happy_node	Carnival Tickets (IOI20_tickets)	C++17	25 / 100	649 ms	92732 KiB

tickets

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

typedef long long ll;

const int MX=1505, of=1505;

ll dp[MX][2*MX], par[MX][2*MX];

int cur[MX];

long long find_maximum(int K, std::vector<std::vector<int>> d) {
        int N=d.size();
        int M=d[0].size();      

        vector<array<int,3>> vals;

        for(int i=0;i<N;i++) {
                for(int j=0;j<M;j++) {
                        vals.push_back({d[i][j],i,j});
                }
        }

        sort(vals.begin(),vals.end());

        ll ans=0;
        for(int i=0;i<N*K/2;i++) {
                ans-=vals[i][0];
                cur[vals[i][1]]++;
        }
        for(int i=N*M-(N*K/2);i<N*M;i++) {
                ans+=vals[i][0];
        }

        vector<pair<int,int>> v;

        for(int i=0;i<N;i++) 
                v.push_back({cur[i]-1,i});

        // for each k, we try to find N/2 nodes with largest cur_i and set it to fill in the negatives, and other N/2 o fill in the positives
        
        vector<int> fr(N), bk(N,M-1);
        vector<vector<int>> s(N,vector<int>(M,-1));

        for(int x=0;x<K;x++) {
                sort(v.rbegin(),v.rend());
                for(int j=0;j<N/2;j++) {
                        auto &[y,i]=v[j];
                        s[i][fr[i]]=x;
                        fr[i]++;
                        y--;
                }
                for(int j=N/2;j<N;j++) {
                        auto &[y,i]=v[j];
                        s[i][bk[i]]=x;
                        bk[i]--;
                }
        }

        allocate_tickets(s);

        return ans;
}

• Subtask 1: 11 / 11
• Subtask 2: 0 / 16
• Subtask 3: 0 / 14
• Subtask 4: 14 / 14
• Subtask 5: 0 / 12
• Subtask 6: 0 / 23
• Subtask 7: 0 / 10