Submission #576549

#	Time	Username	Problem	Language	Result	Execution time	Memory
576549		Arnch	Fun Tour (APIO20_fun)	C++17	0 / 100	3 ms	2656 KiB

fun

#include "fun.h"
#include<bits/stdc++.h>

#define H(x, y) hoursRequired(x, y)
#define A(x, y) attractionsBehind(x, y)
#define Sz(x) x.size()

using namespace std;

const int N = 1e5 + 10;

int dp[N], h[N], d[N], par[N];
bool mark[N];
vector<int> adj[N];

int dfs(int x, int p = 0) {
	int res = x;
	for(auto i : adj[x]) {
		if(i == p) continue;
		h[i] = h[x] + 1;
		int u = dfs(i, x);
		if(h[u] > h[x]) {
			res = u;
		}
	}
	return res;
}

vector<int> createFunTour(int N, int Q) {
	for(int i = 1; i < N; i++) {
		for(int j = 0; j < i; j++) {
			if(H(i, j) == 1) {
				adj[i].push_back(j), adj[j].push_back(i);
			}
		}
	}
	
	int s = dfs(0), t = 0;
	queue<int> pq;
	pq.push(s), mark[s] = 1, par[s] = s;

	while(!pq.empty()) {
		int p = pq.front(); pq.pop();
		if(d[p] >= d[t]) {
			t = p;
		}
		for(auto i : adj[p]) {
			if(mark[i]) continue;
			mark[i] = 1, d[i] = d[p] + 1, pq.push(i);
			par[i] = p;
		}
	}

	vector<pair<int, int> > vc;
	vc.push_back({t, -1});
	int k = par[t];
	while(k != s) {
		if(Sz(adj[k]) == 2) {
			vc.push_back({k, -1}); 
			k = par[k];
			continue;
		}
		int u;
		for(int i = 0; i < 3; i++) {
			if(adj[k][i] != par[k] && adj[k][i] != vc.back().first) {
				u = adj[k][i];
				break;
			}
		}
		vc.push_back({k, u});
		k = par[k];
	}
	vc.push_back({s, -1});

	
	vector<int> ans;
	int r = Sz(vc) - 1, nu = 0;
	bool f = 0, f2 = 0;
	for(int l = 0; l < r; nu++) {
		if(nu & 1) {
			if(vc[l].second == -1 || f == 1) {
				ans.push_back(vc[l].first);
				f = 0;
				l++;
			}
			else {
				f = 1;
				ans.push_back(vc[l].second);
			}
		}
		else {
			if(vc[r].second == -1 || f2 == 1) {
				ans.push_back(vc[r].first);
				f2 = 0;
				r--;
			}	
			else {
				f2 = 1;
				ans.push_back(vc[r].second);
			}
		}
	}
	
	if(vc[r].second != -1) ans.push_back(vc[r].second);
	ans.push_back(vc[r].first);


	return ans;

}

• Subtask 1: 0 / 10
• Subtask 2: 0 / 16
• Subtask 3: 0 / 21
• Subtask 4: 0 / 19
• Subtask 5: 0 / 34