Submission #546319

#	Time	Username	Problem	Language	Result	Execution time	Memory
546319		amunduzbaev	Fun Tour (APIO20_fun)	C++17	100 / 100	249 ms	23400 KiB

fun

#include "fun.h"
#include "bits/stdc++.h"
using namespace std;
#ifndef EVAL
#include "grader.cpp"
#endif
#define ar array
const int B = 894;
int d[B][B];

const int MAXN = 1e5 + 5;
vector<int> edges[MAXN];

vector<int> createFunTour(int n, int Q) {
	if(n == 2) return {0, 1};
	vector<int> d(n), sub(n);
	for(int i=0;i<n;i++){
		sub[i] = attractionsBehind(0, i);
	}
	
	int p = 0;
	for(int i=1;i<n;i++){
		if(sub[i] * 2 > n && sub[i] < sub[p]){
			p = i;
		}
	}
	
	vector<int> c;
	for(int i=0;i<n;i++){
		d[i] = hoursRequired(p, i);
		if(d[i] == 1) c.push_back(i);
	}
	
	int sz = c.size();
	assert(sz >= 2);
	vector<priority_queue<ar<int, 2>>> v(sz);
	for(int i=0;i<n;i++){
		if(i == p) continue;
		int d1 = hoursRequired(i, c[0]), d2 = hoursRequired(i, c[1]);
		if(d1 == d2) v[2].push({d[i], i});
		else {
			if(d1 < d2) v[0].push({d[i], i});
			else v[1].push({d[i], i});
		}
	}
	
	vector<int> P;
	int last = -1; 
	while((int)P.size() < n - 1){
		vector<int> t(sz); iota(t.begin(), t.end(), 0);
		sort(t.begin(), t.end(), [&](int i, int j){
			if(v[i].empty()) return false;
			if(v[j].empty()) return true;
			return (v[i].top()[0] > v[j].top()[0]);
		});
		
		int a = t[0];
		if(a == last && !v[t[1]].empty()) a = t[1];
		
		P.push_back(v[a].top()[1]);
		v[a].pop(); last = a;
		sort(t.begin(), t.end(), [&](int i, int j){
			return (v[i].size() > v[j].size());
		});
		
		if(sz > 2 && v[t[0]].size() > v[t[1]].size() + v[t[2]].size()){
			assert(last == t[1] || last == t[2]);
			int r = t[1] + t[2] - last;
			if(!v[r].empty() && v[r].top()[0] > d[P.back()]){
				P.push_back(v[r].top()[1]);
				v[r].pop();
				last = r;
			}
			
			while((int)P.size() < n - 1){
				P.push_back(v[t[0]].top()[1]); v[t[0]].pop();
				if(v[t[1]].empty() && v[t[2]].empty()) continue;
				if(!v[t[1]].empty() && !v[t[2]].empty()){
					if(v[t[1]].top()[0] > v[t[2]].top()[0]) P.push_back(v[t[1]].top()[1]), v[t[1]].pop();
					else P.push_back(v[t[2]].top()[1]), v[t[2]].pop();
				} else if(v[t[1]].empty()) P.push_back(v[t[2]].top()[1]), v[t[2]].pop();
				else P.push_back(v[t[1]].top()[1]), v[t[1]].pop();
			}
		}
	}
	
	P.push_back(p);
	return P;
}

/*

12 400000
0 1
0 2
1 3
1 4
2 5
2 6
3 7
3 8
4 9
4 10
5 11

*/

• Subtask 1: 10 / 10
• Subtask 2: 16 / 16
• Subtask 3: 21 / 21
• Subtask 4: 19 / 19
• Subtask 5: 34 / 34