Submission #1030500

#	Time	Username	Problem	Language	Result	Execution time	Memory
1030500		happy_node	Carnival Tickets (IOI20_tickets)	C++17	27 / 100	415 ms	108536 KiB

tickets

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

typedef long long ll;

const int MX=1505;

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

int cur[MX], fr[MX], bk[MX];

int N,M;

vector<int> work(vector<pair<int,int>> v) {   
        for(int i=0;i<=N;i++) {
                for(int j=0;j<=N;j++) {
                        dp[i][j]=-1e18;
                        par[i][j]=0;
                }
        }

        dp[0][N/2]=0;

        for(int i=0;i<N;i++) {
                for(int j=0;j<=N;j++) {
                        if(dp[i][j]==-1e18) continue;
 
                        if(j+1<=N && dp[i][j]+v[i].second>dp[i+1][j+1]) {
                                dp[i+1][j+1]=dp[i][j]+v[i].second;
                                par[i+1][j+1]=1;
                        } 
                        if(j>0 && dp[i][j]-v[i].first>dp[i+1][j-1]) {
                                dp[i+1][j-1]=dp[i][j]-v[i].first;
                                par[i+1][j-1]=-1;
                        }
                }
        }

        vector<int> res;

        int cur=N, bal=N/2;
        while(cur>0) {
                res.push_back(par[cur][bal]);
                bal-=par[cur][bal];
                cur--;
        }
        
        reverse(res.begin(),res.end());

        return res;
}

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

        for(int i=0;i<N;i++) bk[i]=M-1;

        vector<vector<int>> s(N,vector<int>(M,-1));

        ll ans=0;

        for(int x=0;x<K;x++) {
                vector<pair<int,int>> options;
                for(int i=0;i<N;i++) {
                        options.push_back({d[i][fr[i]],d[i][bk[i]]});
                }
                vector<int> v=work(options);
                for(int i=0;i<N;i++) {
                        if(v[i]>0) {
                                s[i][bk[i]]=x;
                                ans+=d[i][bk[i]];
                                bk[i]--;
                        } else {
                                s[i][fr[i]]=x;
                                ans-=d[i][fr[i]];
                                fr[i]++;
                        }
                }
        }

        allocate_tickets(s);

        return ans;
}

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