Submission #301439

#	Time	Username	Problem	Language	Result	Execution time	Memory
301439		guangxuan	Carnival Tickets (IOI20_tickets)	C++14	11 / 100	2 ms	896 KiB

tickets

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

long long find_maximum(int k, std::vector<std::vector<int>> x) {
	int n = x.size();
	int m = x[0].size();
    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;
        //cerr<<l[i] << ' ' << r[i] << endl;
        pq.push({x[i][l[i]]-1e9+x[i][r[i]],i});
        neg+=l[i];
    }
    while(neg>n*k/2){
        assert(pq.size());
        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][l[i]]-1e9+x[i][r[i]],i});
        }
    }
    int vmin = 1e9,vmax = 0;
    for(int i=0;i<n;i++){
        //cerr<<l[i] << ' ' << r[i] << endl;
        for(int j=0;j<l[i];j++){
            vmin=min(vmin,x[i][j]);
        }
        for(int j=m-1;j>r[i];j--){
            vmax=max(vmax,x[i][j]);
        }
    }
    long long ans = (long long)(vmax-vmin)*((long long)n*k/2);
    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-=x[i][j]-vmin;
            low[i].push_back(j);
        }
        for(int j=m-1;j>r[i];j--){
            ans-=vmax-x[i][j];
            high[i].push_back(j);
        }
    }
	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",storel[i],storer[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();
            }
        }
    }
    
	allocate_tickets(answer);
	return ans;
}

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