Submission #1082435

#	Time	Username	Problem	Language	Result	Execution time	Memory
1082435		wood	Carnival Tickets (IOI20_tickets)	C++17	11 / 100	1 ms	860 KiB

tickets

#include "tickets.h"
#include <vector>
#include <bits/stdc++.h>
using namespace std;
#define vi vector<int>
#define ll long long
#define pb push_back
#define eb emplace_back
#define p32 pair<int,int>

long long find_maximum(int k, std::vector<std::vector<int>> x) {
	int n = x.size(), m = x[0].size();
	vector<vi> ans;
	if(m==1){
		vi p;
		for(int i = 0; i<n; i++){ ans.pb({0}); p.pb(x[i][0]);}
		sort(p.begin(),p.end());
		ll sum = 0;
		for(int i =0; i<n; i++) sum+=abs(p[n/2]-p[i]);
		allocate_tickets(ans);
		return sum;
	}
	ll result = 0;
	bool finalchoice[n];
	for(int i = 0; i<2*n; i++){
		bool choice[n]; memset(choice,0,sizeof choice); //true if we pick the big card
		int mid = x[i%n][0];
		if(i>=n){ mid = x[i%n][m-1]; choice[i] = true;}
		int lowcnt = 0,highcnt = 0;
		ll sum = 0;
		priority_queue<p32,vector<p32>,greater<>> q;
		for(int j = 0; j<n; j++){
			if(i==j) continue;
			int a = x[j][0], b = x[j][m-1];
			if(a>mid){
				sum+=b-mid;
				highcnt++;
				choice[j] = true;
			}
			else if(b<mid){
				sum+=mid-a;
				lowcnt++;
			}
			else if(mid-a>b-mid){
				sum+=mid-a;
				lowcnt++;
				q.emplace(2*mid-a-b,j);
			}
			else{
				sum+=b-mid;
				highcnt++;
				choice[j] = true;
				q.emplace(a+b-2*mid,j);
			}
		}
		while(highcnt>lowcnt&&!q.empty()) {
			int x = q.top().first, j = q.top().second;
			if(choice[j]){
				sum-=x;
				highcnt--;
				lowcnt++;
			}
			q.pop();
		}
		while(lowcnt>highcnt&&!q.empty()){
			int x = q.top().first, j = q.top().second;
			if(!choice[j]){
				sum-=x;
				highcnt++;
				lowcnt--;
			}
			q.pop();
		}
		if(highcnt!=lowcnt) continue;
		if(sum>result){
			for(int j = 0; j<n; j++) finalchoice[j] = choice[j];
		}
	}
	ans.resize(n);
	fill(x.begin(),x.end(),vi(m,-1));
	for(int i = 0; i<n; i++){
		if(finalchoice[i]) x[i][m-1] = 0;
		else x[i][0] = 0;
	}
	allocate_tickets(ans);
	return result;
}

• 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