Submission #300493

#	Time	Username	Problem	Language	Result	Execution time	Memory
300493		guangxuan	Carnival Tickets (IOI20_tickets)	C++14	76 / 100	3055 ms	65736 KiB

tickets

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

long long find_maximum(int k, std::vector<std::vector<int>> x2) {
	int n = x2.size();
	int m = x2[0].size();
	int all_x[n*m];
	for (int i = 0; i < n; i++) {
		for(int j=0;j<m;j++){
			all_x[i*m+j] = x2[i][j];
		}
	}
	sort(all_x,all_x+n*m);
    long long bans=0;
    vector<vector<int> > banswer;
    for(int mi=max(n*m/2-10,0);mi<min(n*m/2+10,n*m);mi++){
        vector<vector<int>> x = x2;
        int med = all_x[mi];
        cerr << med << endl;
        for (int i = 0; i < n; i++) {
            for(int j=0;j<m;j++){
                x[i][j] -= med;
                //printf("%d ",x[i][j]);
            }//puts("");
        }
        int l[n],r[n];
        int neg = 0;
        priority_queue<pair<int,int> >pq;
        for(int i=0;i<n;i++){
            l[i]=k;r[i]=m-1;
            for(int j=0;j<k;j++){
                if(x[i][j]>0){
                    l[i]=j;r[i]=m-1-(k-j);
                    break;
                }
            }
            //cerr<<l[i] << ' ' << r[i] << endl;
            if(l[i]&&x[i][r[i]]>=0){
                pq.push({x[i][r[i]]-abs(x[i][l[i]-1]),i});
            }
            neg+=l[i];
        }
        bool legit = 1;
        while(neg>n*k/2){
            if(!pq.size()){legit=0;break;}
            pair<int,int> ctop = pq.top();pq.pop();
            int i= ctop.second;
            neg--;
            l[i]--;r[i]--;
            if(l[i]&&x[i][r[i]]>=0){
                pq.push({x[i][r[i]]-abs(x[i][l[i]-1]),i});
            }
        }
        if(!legit||neg!=n*k/2)continue;
        long long ans = 0;
        vector<int> low[n], high[n];
        for(int i=0;i<n;i++){
            //cerr<<l[i] << ' ' << r[i] << endl;
            for(int j=0;j<l[i];j++){
                ans+=abs(x[i][j]);
                low[i].push_back(j);
                if(x[i][j]>0){legit=0;break;}
            }
            for(int j=m-1;j>r[i];j--){
                ans+=abs(x[i][j]);
                high[i].push_back(j);
                if(x[i][j]<0){legit=0;break;}
            }
        }
        if(!legit)continue;
        std::vector<std::vector<int>> answer(n,vector<int>(m,-1));
        pair<int,int> diff2id[n];
        /*for(int i=0;i<n;i++){
            printf("%d %d\n",l[i],r[i]);
            printf("lo: ");
            for(int j:low[i])printf("%d ",j);
            printf("high: ");
            for(int j:high[i])printf("%d ",j);
            puts("");
        }*/
        for(int r=0;r<k;r++){
            for(int i=0;i<n;i++)diff2id[i] = make_pair(high[i].size()-low[i].size(),i);
            sort(diff2id,diff2id+n);
            for(int i=0;i<n;i++){
                if(i<n/2){
                    int x = diff2id[i].second;
                    answer[x][low[x].back()] = r;
                    low[x].pop_back();
                }
                else{
                    int x = diff2id[i].second;
                    answer[x][high[x].back()] = r;
                    high[x].pop_back();
                }
            }
        }
        if(ans>bans){
            bans=ans;
            banswer=answer;
        }
    }
    
	allocate_tickets(banswer);
	return bans;
}

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